Production, transport and use of prefabricated components in shoreline and floating structures

ABSTRACT

Novel prefabricated structural components such as precast concrete boxes having forms including rectangular parallelepipeds and hexagonal cylinders are disclosed which can be assembled together and/or with structural shapes disclosed in U.S. Pat. Nos. 5,697,736 and 5,697,473 to form waterfront structures such as seawalls, levees and breakwaters. Novel methods of waterborne transport and installation of the boxes and arrays thereof are disclosed, including modular vessels having bow and stern sections which can be connected directly together or mounted to a mid-section containing assemblies of such boxes, other structural elements or other vessels such as floating drydocks. Modular vessels can be assembled with any or all of the bow, midship and stern sections comprising honeycomb arrays of vertically-oriented hexagonal boxes.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of Veazey's U.S. Ser. No.10/731,263 filed on Dec. 8, 2003, now U.S. Pat. No. 7,007,620 which isitself a continuation-in-part of Veazey's Ser. No. 10/314,099 filed onDec. 7, 2002, now U.S. Pat. No. 6,659,686, which is a divisional ofVeazey's U.S. Ser. No. 09/776,971 filed on Feb. 5, 2001, now U.S. Pat.No. 6,491,473. These patents are all incorporated herein by reference.Also incorporated herein by reference is U.S. Pat. No. 5,697,736 ofVeazey et al.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This application pertains to the manufacture, transport, use andinstallation of a variety of prefabricated boxlike components to formterrestrial, shoreline and floating structures for various purposes,including hurricane and flood pre-event mitigation and post-eventrecovery, national defense and homeland security.

This application also pertains to ships and methods for transportingprecast concrete structures of various sizes and shapes which aresuitable for installation as integrated systems to form seawalls andvarious shoreline reinforcement systems for limiting shoreline erosionby rivers, lakes, oceans, sounds and other major bodies of water, aswell as terrestrial structures for terracing, dams, bridges, buildings,etc. The application further relates to ships which are at leastpartially formed of precast concrete structures, preferably structureswhich have hexagonal cross sections and can be assembled into honeycombarrays to form portions of the ship hulls which have relatively highstrength-to-weight ratios.

2. Summary of Relevant Art

The parent patents referred to above provide a summary of relevant priorart.

Additionally, International Publication No. WO 90/08059 (Jul. 26, 1990)discloses “Floating Concrete Modulate [sic] Platforms” assembled ofhexagonal modules with stiffness walls between opposite vertex(es),joined by prestressed cables in the “enlargement spaces”. Some uses havebeen made of commercial metal shipping containers for terrestrialstructures such as shelters, sheds, offices, workshops and the like;see, e.g. publications of SEA BOX INC. of New Jersey, recently viewed atwww.seabox.com.

While many techniques have been developed for reinforcing shorelines, asdescribed in that patent and various publications of the U.S. Army Corpsof Engineers, there is still considerable room for improvement.Applicant's company Seament Shoreline Systems, Inc. of Virginia and itssubcontractors have completed several shoreline installations using thecomponents and methods disclosed in the above patents. The Corps ofEngineers publication “LOW COST SHORE PROTECTION . . . a PropertyOwner's Guide” discloses at page 154 the use of precast open concreteboxes filled with sand to form waterfront sills to retain perchedbeaches. U.S. Pat. No. 5,697,736 discloses in columns 8-9 the use ofprecast concrete boxes as alternatives to Double “T” units (discussedbelow) for constructing pier-groins extending seaward from a seawall andfor use in forming underwater and near-shore) breakwaters. Columns 12-13and FIGS. 20 to 25 discuss the use of such concrete boxes to formfloating pier assemblies.

Catalogs of Admiral Marine Co. (Staten Island, N.Y., New Orleans,Oakland, CA and Chicago) and Peck & Hale (West Sayville, N.Y. andKowloon, HONG KONG, PRC) disclose various metal fastening devices whichcould be employed to connect certain components of the present inventionto form structures.

Normally, large stone rip-rap revetments, groins or breakwaters havebeen used for such protection. However, these methods require that alarge total mass of materials be transported to the site. Such rocks aredifficult to handle, cannot be interconnected or floated into place andare not easily relocatable. Furthermore, such rocks are not amenable tointermodal transport or use in a modular system.

Despite the state of the art and improvements such as those disclosed inApplicant's patents cited above, recent natural disasters andinternational conflicts have demonstrated the need for continuingimprovements in the construction of shoreline and floating structures toprotect shorelines from storms, floods and the like and to protectcritical areas of national coastlines or military positions in operatingareas.

SUMMARY OF THE INVENTION

An object of the present invention is to provide easily transportableconstruction components which can be used to control shoreline erosion.As another object, such components should be provided in sizes, shapesand proportions which are compatible with existing trucks, railcars andmaritime transportation modes (i.e., intermodal transportation) as wellas adapted to existing materials handling equipment. As a furtherobject, the components should be transportable in segments so that theycan be moved into positions for installation through crowded beachfrontareas, by land, water or aircraft such as heavy lift helicopters, blimpsor dirigibles.

Another object of the invention is to provide such constructioncomponents as partially-closed containers which are light in weight butcan be filled with available liquid or solid materials at theinstallation site to substantially increase their mass at little cost. Afurther object of the invention is to provide construction componentswhich can be filled with solids, gases or liquids to increase theirmasses when installed as part of a structure, simultaneously serving assealed storage containers for such materials for later use.

An additional object of the invention is to provide constructioncomponents which have the largest masses practicable when filled withballasting material and installed to form structures. Maximizing themass of such components is desirable to equip the structures to resistthe large forces generated by storm waves, currents, floods, mudslides,earthquakes and other natural disasters. Such maximizing of mass canhave similar applications in combat engineering, where enemy artillery,bombardment and demolitions may be encountered.

Still another object of the invention is to provide intermodal sets ofprecast concrete boxes which can be used as fixed or floatingconstruction components for various civil, marine, commercial ormilitary construction projects. Such components could be connectedtogether to form causeways, fixed or floating bridges, dams, drillingrigs, floating or fixed airport runways or helicopter pads, temporary orpermanent shipping ports, temporary military or naval facilities such asport, repair, supply or airport installations, “container ships”,relocatable modular waterfront structures such as houses, and many otherapplications.

Still another object of the invention is to provide methods ofinstalling precast concrete boxes in underwater positions bytransporting them on floating vessels and/or floating them intoapproximate position and sinking them into their final installedpositions or assembling them into floating structures. A related objectis to provide vessels which are suitable for transporting such boxes,either as deck cargo or as a floating, removable component of the vesselitself. Another related object is to provide precast concrete componentswhich can be interconnected to form portions of the hull structures ofsuch vessels.

Certain of these objects and aspects of the invention are achieved byembodiments described below.

In accordance with the present invention, precast concrete boxes areprovided, preferably having the form of rectangular parallelepipeds,which can be transported by water and assembled to form shorelinestructures. As alternatives to such precast concrete boxes, similarboxes can be formed of materials selected from the group consisting ofmetal, wood, plastics and polymeric composites. Boxes of such materialscan be coated on at least their outer surfaces with concrete to formboxes having the properties of precast concrete boxes. Boxes of metals,concrete or plastic can be coated with various suitable materials tomake them resistant to weathering, liquids and corrosion. Any of theseboxes can be formed with closed cross-sections which are hexagonal orhalf-hexagonal (i.e., a hexagon cut in half, from edge to edge or fromside to side).

When precast of concrete, these boxes can contain reinforcements ofmetallic and/or nonmetallic materials, and preferably include supportscast into at least a portion of the outer edges of the boxes.Reinforcing materials can include fibers, strands, cords, meshes or rodscomprising metals, polymer composites and carbon, polymer or glassfibers. Such supports can comprise angle or bar stock comprising metals,composites or other suitable materials. Additionally or alternatively,the hexagonal and half-hexagonal boxes can contain such reinforcementsin at least a portion of the top, bottom and side panels thereof. Themetallic and/or nonmetallic reinforcements can comprise cables,reinforcing bars and beams of various suitable sizes and cross sections.Such boxes used for assembling floating platforms and/or vesselspreferably have a completely open and unobstructed cross section tofacilitate their employment for useful spaces within such platforms orvessels. This is facilitated by the use of suitable reinforcing means asdiscussed above.

Hexagonal and half-hexagonal boxes to be used for such floatingstructures can have either hexagonal or circular inner cross sections,and optionally can include longitudinal holes or channels cast intotheir side panels or corner portions thereof to provide for runningcables, tubing and the like. Alternatively, if a completely unobstructedinner cross section is not required, structures can be installed withinthe boxes and attached to the bases or bottom surfaces thereof to carrysuch wires or the like. As with other precast concrete boxes disclosedherein and in parent applications, the side walls and/or bottoms of thehexagonal and half-hexagonal boxes can have suitable drain/vent holes,fittings and the like. The sides of the boxes can contain passagesadapted for the introduction of pressurized water and/or air from thetop to assist in “jetting in” the bases of the boxes on the bottom of abody of water or in soft soil. The boxes can be cast of concrete byconventional means using forms, as discussed further below, and wheredesired can be cast without bottom surfaces or bases to form hexagonalor half-hexagonal open cylinders.

Mobile apparatus for casting concrete boxes of any of the shapesdiscussed above can be assembled aboard barges, floating platforms orfloating drydocks. Floating drydocks having bottom hulls with flat innerbottom surfaces, upright side walls and at least one crane mountedthereon (or separate sections thereof) can be transported to remotesites carrying such molding apparatus, using the modular vesselsdiscussed above, and then provided with materials and workers from shoreand/or by barges to manufacture quantities of the precast boxes neartheir points of use.

The precast concrete boxes of the invention can be interconnected bymechanical fastener means to form bundles or assemblies like log boomsto be towed or otherwise transported over water. Further in accordancewith the invention, such interconnected groups of concrete boxes whichform a large rectangular mass can be transported by a self-propelledvessel for transporting floating objects which comprises separate bowand stern sections adapted to be removably fastened together usingmechanical means to form the vessel alone. When used for transportingsuch assemblies of boxes (or other interconnected groups of floatingobjects such as logs, containers, tanks, floating drydocks or the like),the two sections of the vessel are separated and connected to the endsof the group of boxes to form a “stretched” vessel in which the group ofboxes forms a midship section. The vessel is provided with conventionalpropulsion systems (in at least the stern section), thruster propulsionunits to aid in maneuvering, anchors and power supplies for theiroperation and at least one crane for unloading and emplacing the boxesor other cargo at destination.

A preferred embodiment includes the bow and stern sections describedabove removably attached to at least a portion of a floating drydock(some larger drydocks can be moved in sections) which is fastened to thebow and stern sections using similar mechanical fasteners as employedfor arrays of rectangular boxes or other cargo. This permits thetransport of floating drydocks safely to remote locations where they maybe used for their conventional purposes or to set up mobile concretemolding operations for the modules of the present invention.

The group or array of boxes forming the midship section for transport bysuch a vessel can be either boxes forming rectangular parallepipeds ofintermodal sizes and proportions, or boxes of hexagonal andhalf-hexagonal cross sections which are oriented vertically andinterconnected to form a honeycomb array. Furthermore, such boxes ofhexagonal and half-hexagonal cross sections can be interconnected inhoneycomb arrays to form at least a portion of the bow and sternsections of such vessels as well as a midship section for transportingcargo. Such bow and stern sections (and optionally, designatedindividual boxes or arrays thereof) are preferably constructed andinstalled so as to be removably attachable from the midship sectionalong defined lines of separation. Such honeycomb arrays can beassembled by interconnecting the boxes with mechanical connectors andinstalling optional tensioning cables to maintain the form and integrityfor the various sections to form an integrated hull structure consistingessentially of precast concrete boxes having hexagonal or half-hexagonalcross sections. Such hull structures can be configured to have at leastone removably attachable portion such as the bow and stern sections andindividual boxes or arrays thereof discussed above.

In addition to forming portions or substantially complete hulls ofself-propelled vessels as described above, horizontal arrays ofvertically-oriented hexagonal and half-hexagonal modules (and verticalarrays thereof) can be assembled to serve a variety of functions whileafloat in water such as coastal waters, estuaries and along shorelines.They can be emplaced along shorelines to form at least temporary portsor harbors offering shelter and working areas for vessels of any size,given sufficient draft in the water where installed. They can beemplaced and anchored offshore to form platforms for mooring vessels ofvarious sorts to load and/or off-load cargos ranging from large shippingcontainers to petroleum products and other liquids, break bulk cargo orsmaller shipping crates. Where necessary, mooring space can be providedfor lighters, landing craft and small craft for transportation and/orsecurity purposes. Such platforms can be provided with power plants,electric utilities and other auxiliary services, propulsion means for atleast maneuvering into position, electronic communications means and avariety of sensors, including radars and detectors for electromagneticradiation in various frequency ranges.

Further in accordance with the invention, the precast concrete boxes ofthe invention can be installed in the water along a shoreline by sealingall inlets below the expected waterline of the installed boxes, placingthe boxes in the water and floating them into position, then openingsufficient water inlets and air outlets to allow the boxes to sink intotheir assigned places. In preferred embodiments, these inlets andoutlets can be opened remotely by signal means, and directional guidancecan be provided to the boxes while they are being sunk into position. Agroup of such boxes can be interconnected and emplaced beneath the waterto form a submerged breakwater or reef by positioning the connectedboxes atop a flat deck of a vessel, emplacing an anchor on the bottomnear the planned installation position and attaching same to a cableslidably connecting the boxes on deck, launching the boxes into thewater while the vessel proceeds forward away from the anchor, thenmaneuvering the boxes into end-to-end contact and clamping the resultingstring of boxes into place on the cable, placing the resulting floatingstring of boxes into position directly above the planned installationposition, and finally, sinking the boxes while guiding them into finalposition by securing the forward end of the cable to a second anchor atthe opposite end of the string from the first anchor and applyingtension to the cable from the vessel. These methods and techniques canalso be employed for installation of the hexagonal and half-hexagonalboxes disclosed herein, either individually or in arrays.

The vessel used can be a barge, a vessel with a bow door and ramp [suchas Navy landing ship tank, (LST) landing craft mechanized, (LCM) landingcraft vehicle and personnel (LCVP) and the like] or a vessel with anafter well deck affording access to the water for floating boxesdirectly into the water [such as a Navy landing ship dock (LSD)]. Acontainer ship with a flat deck and cranes to hoist the boxes from decklevel to water level can also be used. The Military Sealift Command hasseveral suitable types of ships available, including a “crane ship”.

Additionally, vessels can be custom designed to transport and/or installboxes of rectangular, hexagonal and other shapes, either individually orin arrays, based upon the modular vessels disclosed herein, includingthose comprising sections incorporating honeycomb arrays of hexagonaland (optionally) half-hexagonal modules.

Further in accordance with the invention, hexagonal and half-hexagonalconcrete boxes can be precast with metal and/or nonmetallic reinforcingmeans in at least the sides thereof by steps comprising precastingindividual modules either right side up or upside down using metal formssometimes called tunnel forms. When desired to form a vertical array ofmodules, Such modules can be poured sequentially atop the previouslycast modules with connecting reinforcing means to form an integratedstructure much like a multi-story tower or building. Alternatively,individual modules can be cast, cured, removed from the forms and laterconnected together by interconnecting notches or grooves at one endsized to fit the open end of an adjacent module and various mechanicalconnecting means to form vertical arrays. Linear arrays can also beproduced at the casting site by fastening pluralities of modulestogether edge-to-edge, with the size limited only by hoisting andtransport means. The finished precast hexagonal and half-hexagonal boxespreferably offer the advantage of an open and unobstructed internalcross section from top to bottom, permitting the use of such interiorspaces for a variety of purposes in structures comprising such boxes.

Precast concrete boxes of hexagonal, half-hexagonal and rectangularcross sections can be produced in quantity using assembly plantscomprising forms, concrete mixers, cranes or other suitable liftingequipment, and reinforcing materials. The process includes steps ofpositioning reinforcing materials in the forms, mixing concrete(optionally with fiber or other suitable reinforcement included),pouring suitable amounts into the forms, curing the cast units,stripping the forms from the units and allowing the cast units to hardensufficiently to allow moving or use. Such plants can be permanent or canbe set up temporarily near suitable sources of sand, gravel andnavigable waterways and/or near sites where shoreline or floatingstructures are to be assembled and/or repaired. As discussed elsewhereherein, barges or floating drydocks can be used to set up such mobileplants.

Another aspect of the invention involves the use of transportation orshipping containers of metal or other materials as components for theassembly of temporary or permanent shoreline or shallow water structuresmuch as disclosed in Applicant's previous patents and further below,which employed precast concrete boxes having the form of rectangularparallelepipeds. Such containers of metal or other materials can becoated, either on site or prior to transport to a construction site,with layers of concrete, using conventional spray techniques such as“Gunite” or Shotcrete technologies. Alternatively, they can be coatedwith rust resistant synthetic coatings such as three part mixturescontaining zinc, coal tar derivatives, polyurea coatings and epoxyresins by conventional means including spraying, brushing, dipping andthe like. These rectangular containers of metal or other materials canbe fitted with partitions, watertight lids or closures, valves andfittings for admitting water and blowing water out to float thecontainers, as disclosed below and in Applicant's previous patents.

In addition to the shoreline structures previously disclosed,prefabricated rectangular boxes of the invention, whether precastconcrete or standard metal shipping containers having certainmodifications, can be used for the construction and repair of levees(the embankments or berms bordering riverbanks to prevent overflows athigh water levels), dikes, dams, breached barrier islands and the like.The adaptation and use of surplus metal shipping containers, which oftenaccumulate in port areas such as New Orleans and Houston, can beparticularly advantageous. Arrays of rectangular boxes can be floatedinto place, positioned and sunk into place under water to form thecentral support for a levee under construction or repair, for example.When urgent repairs to ruptured levees, breached barrier islands orsimilar structures are required, floating arrays of boxes can be movedinto position by suitable means, sunk into position where needed,secured in place and the process repeated to form at least a temporarybarrier to reduce or prevent the flow of water through the damaged leveeportions. Similar construction and repair techniques can be employedwith the prefabricated rectangular, hexagonal and half-hexagonal modulesof the invention, under non-emergency conditions.

When the hexagonal modules of the invention are used to providepermanent construction or repairs or levees, dams and the like, at leastone horizontally divided section can be installed which provides a“water gate” to permit water to pass from one side to the other,normally from the river towards the bank or from the upstream side of adam downstream. Such gates can comprise linear arrays of modulespositioned on guide means to permit their movement up and down, theirmovement above or below a certain level allowing water to flow.Ballasting means comprising suitable water and/or air pumps, plumbingand valves are provided to allow such gates to be ballasted so as tosink downward, shutting off water flow through the “gate;” when desired,the modules in the gate can be deballasted or blown to increase buoyancyso that the gate rises to allow water flow. Suitable means are providedto secure such gates in position when open and closed. In a preferredembodiment for use in river delta areas, instead of flowing directlyover the river bank, water flowing through the gate enters a reservoirformed by an array of vertical hexagonal modules arranged in asemicircular or any other suitable pattern. This permits excess water tobe drawn from the river at high flood stages and retained for a time.The module array(s) forming such reservoirs can provide further fluidcontrol means to allow water (and entrained silt) to be released fromthe reservoir at various desired rates depending upon circumstances,escaping into surrounding wetlands to maintain their desired state offlooding with entrained silt.

In addition to forming shoreline structures including seawalls, erosioncontrol arrays, piers and breakwaters, the rectangular and hexagonalmodules disclosed herein can be used to construct or improve dwellingstructures or other buildings near the shoreline, e.g. in barrier islandor flood-prone areas. Such modules can be used in various arrangements,whether singly or in linear arrays, to provide elevated supports forbuildings (like the “stilts” used in the tropics and certain beachcommunities) to allow waves or floods of predetermined height or depthto pass under the structure without significant harm. Such modules canbe ballasted with sand, gravel or the like, and can have openings aboveground level to permit flooding at high water to provide furtherballast.

In an alternative embodiment, rectangular modules can be used to providewatertight foundations or basements for houses or other small structuresin storm or flood-prone areas, comprising watertight outer sidewalls andfloors substantially corresponding to the outer walls of the house orother structure and fastened securely thereto to provide support for thefull weight of the structure. Access from at least the first or groundfloor of the structure can be provided via normal doors and stairways.Partitions within the basement can comprise portions of the modulesused. Optionally, watertight doors which can be closed tightly againstresilient gaskets by means of a lever or other convenient mechanicalactuators (such as commonly used aboard seagoing vessels) can be usedfor access to the basement, whether horizontal doors from outside orbetween basement rooms or vertical access from the structure above.

Boxes assembled and interconnected to form an array which is thenconnected to separate bow and stern sections of a vessel to form themidsection of such a vessel can be transported from an origin to adestination for installation to form shoreline structures by serving aspart of the vessel en route. At destination, the boxes can be removedfrom the vessel midsection, either individually by crane(s) or bydisconnecting the midsection from the vessel, and floated into positionsfor installation to form shoreline and/or underwater structures asdescribed elsewhere herein. Boxes can be disconnected from the adjacentboxes in the array, whether the midsection array is removed from orstill connected to the vessel, and deposited in the water by using thecrane(s). When the midsection is removed and the bow and stern sectionsof the vessel reconnected to form a more compact vessel, the vessel canbe maneuvered to tow groups of boxes or to remove them from theindependently floating midsection array and place them into the water byuse of the crane(s). Alternatively, small tow or pusher boats can becarried on deck by the vessel and used to tow or maneuver the boxes,individually or in connected groups, into position for installation.

Arrays of rectangular and/or hexagonal and half-hexagonal modules can beinstalled along shorelines above and below the normal tidal range (whereapplicable) or water levels to prevent or repair erosion, provide secureseawalls or bulkheads, breakwaters and shoreline structures such aspiers, wharves or similar moorings for small craft or larger vessels andto connect same with the shore. The use of hexagonal and half-hexagonalmodules offers many options for emplacing linear arrays firmly inshorelines where desired, and also to easily form extensions of sucharrays forming angles of either 60 or 90 degrees to the original array.Such arrays can be useful as both seawalls and breakwaters, dependingupon their location and mode of installation. Half-hexagonal modules canbe used to fill in areas between adjacent hexagonal modules to form asubstantially smooth or flush contour, although there are alsoadvantages to leaving a surface with V-shaped grooves or “notches”exposed to the water. Such modules can be employed underwater and/orprotruding above normal low tide or water levels to provide breakwatersto shield such shoreline structures from surf, storm surges or otherwaves.

Many types of floating platforms can be constructed using prefabricatedmodules and the modular ship concepts disclosed herein. Hexagonal andhalf-hexagonal modules are preferred for assembling such vessels, due tothe high strength-to-weight ratio of the resulting honeycomb arrays. Oneembodiment provides a hull structure comprising vertical arrays ofhexagonal modules forming honeycomb array structures (and preferablyconsisting essentially of same), preferably shaped to have defined bowand stern sections which are removably attached along lines ofseparation and using half-hexagonal modules to provide smooth sidecontours. Such hull structures can optionally have at least one moduleand/or section (such as bow or stern sections) which is removablyattachable along defined lines of separation. Separable modules can beequipped and used as escape vehicles or the like. Portions of the hullmodules can be employed for engineering spaces, tanks, storage spacesand the like. Rectangular and/or hexagonal modules can be installed atopthe hull structure to form a superstructure which can be subdivided intospaces for operations, berthing, dining and other uses, depending uponthe size and assigned mission of the vessel. Preferably at least oneelevated portion is provided above the superstructure (using, e.g. atleast one large hexagonal module) to provide an observation tower and/orpilot house for operating the vessel. Such vessels with hulls comprisinghexagonal and half-hexagonal modules and superstructures of variousconfigurations can be used as houseboats, temporary carriers ofnavigation aids, observation platforms and in many other usefulapplications. Single hexagonal modules or vertical arrays thereof can beused as ocean sensor buoys floating vertically in the water and similardevices.

Floating platforms of the invention can be equipped with manyaccessories for the missions assigned, including military and fishingequipment, sensors, navigational aids and recreational equipment. Manyof these items can be installed in a modular fashion in the interior ofone or more vertical module, so that they can be readily removed andreplaced for repair, upgrade or mission change. Floating platforms ofeven relatively modest size, whether self-propelled or stationary, canbe outfitted as “service stations” for small patrol craft and helicopterpads, permitting prompt extension of required forces into areas ofcombat or natural disasters requiring search, rescue and medicalevacuation services or offshore observation and intercept.

Floating platforms or vessels of various types comprising rectangularand/or hexagonal and half-hexagonal modules may be employed or emplacedin ocean or offshore areas where they will be exposed to rough waters,swells, high winds and other characteristics of stormy weather. Toalleviate the effects of such winds and waves, they can be outfittedwith sections on at least two sides which can take on water from wavesimpacting the side, taking on energy which can be harnessed and put touse, e.g. through employment of pressurized water in variousapplications. Further, apparatus can be installed (including pumps,lines, valves, sensors and control systems) which permits ballasting anddeballasting (or blowing) portions of the side modules to place thevessel at the desired draft and control roll and/or pitch.

An embodiment of the floating platforms disclosed herein comprises ahull section comprising vertical honeycomb arrays of hexagonal (andoptionally, half-hexagonal) modules having an opening in the bottom opento the water in which the platform floats, of a size and configurationsuitable for accommodating a submarine within the water which enters toform a “moon pool”. A superstructure comprising similar arrays ofhexagonal modules forms a roof or canopy over at least a portion of themoon pool, allowing a submarine to enter from a submerged state withoutobservation from above water. A related embodiment provides a removablestern portion or portions which can be removed by disconnecting alongdefined separation lines, ballasted and lowered below the level of thebottom of the platform, or opened and moved aside on hinges. Thisembodiment permits a variety of small craft or surface vessels, as wellas submarines, to enter from the stern area of the platform for shelter,maintenance or the like.

Additional objects and advantages of the present invention are describedin, and will be apparent from, the following detailed description ofpreferred embodiments together with the drawings and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a prior art “L-wall” from U.S. Pat. No.5,697,736.

FIG. 2 is a sectional view of an inverted T-shaped unit from the samepatent.

FIG. 3 is a sectional view of a conventional “double T” or pi-shapedunit from the same patent.

FIG. 4 is a perspective view of precast concrete boxes from the samepatent.

FIG. 5 is a side view of an improved “L-wall” for use in the presentinvention.

FIGS. 6 and 7 are sectional views of accessories in use with the L-wallsof FIG. 5.

FIGS. 8 and 9 illustrate further refinements of the L-walls of FIG. 5.

FIGS. 10-12 are plan, side and end views of improved precast concreteboxes of the present invention.

FIGS. 13A, 13B and 13C are plan, side and end views, respectively, ofintermodal boxes of the invention arranged on deck for transport.

FIGS. 14A and 14B are end and plan views, respectively, of an underwaterbreakwater assembled of such boxes.

FIGS. 15-17 are plan, side and end views of such precast boxes withprovisions for sinking same in water and raising them thereafter.

FIG. 18 is a side view of a precast concrete box of the presentinvention floating near the surface of a body of water.

FIG. 19 is a top view of a series of precast concrete boxes connectedtogether to form a structure.

FIG. 20 is a side view of a precast concrete box of the invention whichhas been sunk to the bottom in a body of water.

FIGS. 21-23 illustrate anti-scour plates for use with the precastconcrete boxes of the invention.

FIGS. 24 and 25 illustrate connecting devices for use with the precastconcrete boxes of the invention.

FIGS. 26-29 illustrate the employment of various connecting devices toconnect such boxes.

FIG. 30 is a sectional view of a quick connection for an air hoseinserted into a hole in the tank which can be employed to refloat theprecast concrete boxes of the invention.

FIGS. 31-33 are end, plan and side views, respectively, of a waterfrontboathouse constructed with precast concrete boxes of the presentinvention, resting upon the bottom.

FIGS. 34 and 35 are end and plan views of a larger floating boathouseconstructed using three large precast concrete boxes of the invention.

FIGS. 36 and 37 are plan and side views of a conventional fixedboathouse using piles surrounded by concrete boxes to protect theboathouse from ice.

FIGS. 38-40 are side, top and end views of a modified precast concretebox of the invention which is suitable for building bridges.

FIG. 41 is a top view of a shoreline reinforcement system assembled fromprecast concrete boxes of the present invention.

FIG. 42 is a side sectional view of the shoreline system of FIG. 41.

FIGS. 43-45 are side views of a ship designed to incorporate a moduleassembled of precast concrete boxes of the invention as the parallelmidbody of the ship in order to transport same.

FIGS. 46-48 are side views illustrating the launching of floatingprecast concrete boxes of the invention from a ship or barge and thesinking thereof to form an underwater structure.

FIGS. 49 and 50 are end and plan views, respectively, of a dwellingstructure assembled from precast concrete boxes.

FIGS. 51 and 52 are perspective views illustrating shellfish habitatsbased upon precast concrete boxes of the invention, with two types ofremovable concrete tops.

FIGS. 53 and 53A are perspective views illustrating another version ofshellfish habitat with removable top, including means for hoisting theassembly from underwater.

FIG. 54 illustrates a seawall and beach reinforcement system including aseawall, at least one groin built of inverted “T” structures, at leastone row of inverted “T” structures parallel to the seawall, and flexiblecloth-concrete cable or chain assemblies emplaced in conjunction withsame.

FIGS. 55 and 56 illustrate a seawall and reinforcement system designedfor installation along the Potomac River shoreline in Virginia,including groins perpendicular to the seawall.

FIGS. 57 and 58 are top views of a ship constructed of preformed hollowcomponents having a hexagonal cross section, assembled in a honeycombarray.

FIGS. 59A to 59F are side views of individual hexagonal modules of theship of FIGS. 57 and 58.

FIG. 60 is a side view of a number of hexagonal modules assembled in asingle layer and honeycomb array to form a modular portion for use in aship.

FIG. 61 is a side view of hexagonal modules assembled as in FIG. 60, butwith four separate layers of honeycomb arrays superimposed, oralternatively three horizontal decks emplaced within a single deepmodule.

FIG. 62 is a top view of a hexagonal module suitable for use inassembling the arrays illustrated above.

FIG. 63 is a side view of the hexagonal module of FIG. 62.

FIG. 64 is an overhead perspective view of a floating drydock.

FIG. 65 is an overhead perspective view of a modular ship of theinvention incorporating a floating drydock as the midship section.

FIG. 66 is a side view of a metal shipping container adapted for use instructures of the invention.

FIG. 67 is a top view of a breakwater and groin structure constructed ofrectangular boxes.

FIG. 68 is a top view of the structure of FIG. 67 covered over with apier.

FIG. 69 is an overhead view of a levee or barrier island breach repairoperation.

FIG. 70 is a top view of barrier island rebuilding, using rectangularbox modules.

FIG. 71 is an end sectional view of the installation of FIG. 70.

FIG. 72 is a side view of an installation of rectangular box modules ona sandy bottom.

FIG. 73 is a side view of the installation of FIG. 72 at higher waterlevel.

FIG. 74 is a top view of a floodgate comprising hexagonal modules.

FIG. 75 is a side view of a floodgate assembly in closed position.

FIG. 76 is a side view of the floodgate assembly of FIG. 75 in openposition.

FIG. 77 is a top view of the floodgate of FIG. 74 showing supports andguides.

FIG. 78 is a top view of a floodgate assembly as in FIGS. 75 and 76which is installed in a levee or dam comprising hexagonal modules.

FIG. 79 is a sectional schematic side view of a modular vessel with astabilization system installed.

FIG. 80 is a side sectional view of a wave energy conversion apparatus.

FIG. 81 is a top view of a hexagonal module illustrating moldingtechniques.

FIG. 81A is a side sectional view of the module of FIG. 80.

FIG. 82 is a top view of a hexagonal module containing wireways in theinner surface of intersections of the sides.

FIG. 83 is a top view of a hexagonal module with a circular inner crosssection.

FIG. 84 is a side view of a vertical array of hexagonal modules.

FIG. 85 is a top view of the array of FIG. 84.

FIG. 86 is a top view of a hexagonal module with a circular inner crosssection, wireways in the corners of the walls and a circularcolumn/wireway in the center.

FIG. 87 is a top view of a hexagonal module with a circular inner crosssection and a hexagonal inner column with a circular hole therein.

FIG. 88 is a side view of a set of vertically interlocking hexagonalmodules.

FIG. 89 is a side view of the module set of FIG. 88 joined together toform a column or vertical array.

FIG. 90 is a top view of a module from FIG. 88 showing grooves on thetop which allow it to interlock with other modules.

FIG. 91 is an end view of a module casting plant assembled on a floatingdrydock.

FIG. 92 is a top view of the plant and drydock of FIG. 91.

FIG. 93 is a side view of a houseboat comprising arrays of hexagonalmodules.

FIG. 94 is a top view of a houseboat as in FIG. 93, having asuperstructure comprising rectangular modules.

FIG. 95 is a top view of a houseboat as in FIG. 93, having asuperstructure comprising hexagonal modules.

FIG. 96 is a side view of a lifeboat or escape module based upon atleast one hexagonal module.

FIG. 97 is a top view of a flood-proof basement or foundation comprisingrectangular modules.

FIG. 98 is an overhead view of large arrays of hexagonal modules beingjoined together.

FIG. 99 is an overhead view of a floating platform which accommodates asubmarine.

FIG. 100 is a side view of the platform of FIG. 99.

FIG. 101 is a stern view of the platform of FIG. 99.

FIG. 102 is a top view of a seawall constructed of horizontal arrays ofhexagonal modules.

FIG. 103 is a top view of a linear array of hexagonal modules arrangedtwo deep.

FIG. 104 is a top view of a single array of hexagonal modules includinghalf-hexagonal modules to produce flush surfaces.

FIG. 105 is a top view of a linear array of hexagonal modules two deepand with flush sides.

FIG. 106 is a side view of an array of hexagonal modules two deep andforming a levee or wharf.

FIG. 107 is an overhead view of a port facility constructed principallyof hexagonal modules.

FIG. 108 is a top view of a floating or bottomed platform constructed ofhexagonal modules.

FIG. 109 is a top view of a floating platform constructed of hexagonalmodules which includes an open inner area and an entrance which can beopen or closed.

FIG. 110 is an end sectional view of a hexagonal module being floatedinto place to reinforce a levee.

FIG. 111 is a side sectional view of the hexagonal module of FIG. 110being emplaced vertically against the levee.

FIG. 112 is a side sectional view of a hexagonal module emplacedvertically landward to form a central spine for a new reinforced levee.

FIG. 113 is an end sectional view of hexagonal and rectangular modulesforming the spine of a levee.

FIG. 114 is a top view of the levee and modules of FIG. 113.

FIG. 115 is a top view of a levee with rectangular boxes being emplacedfor repairs or reinforcement.

FIG. 116 is an end sectional view of the levee and modules of FIG. 115.

FIG. 117 is an end cutaway view of a levee containing a spine ofvertical arrays of rectangular boxes with horizontal collars attached.

FIG. 118 is a top view of the spine removed from the levee of FIG. 117.

FIG. 119 is a side view of the spine of FIG. 118 with the collarsdetached.

FIG. 120 is a side view of a hexagonal module used in floatingplatforms, showing allocation of space at various levels.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

It should be understood that the following description of presentlypreferred embodiments of the present invention is merely representativeof many possible embodiments and thus is not intended to limit the scopeof the invention. In the following description, like structures will bereferred to by similar numerical designations.

Referring now the drawings, FIG. 1 is a sectional view of an L-wall asdisclosed in the earlier patent. FIG. 1 illustrates an L-shapedstructural member (2) of the above patent, intended for use in retainingwalls, seawalls and the like. Vertical wall or stem portion (4) issubstantially perpendicular to footer (6), and vertical key (8) extendsbelow the lower surface of the footer, essentially in line with thevertical wall portion. Angular splash plate (10) protrudes from wall (4)opposite footer (6), forming an obtuse angle ( ) downward from the walland forming an acute angle ( ) with the plane of the footer base. Thethicknesses of the vertical wall and footer portions can vary, beingthickest near their intersection where stresses are greatest andtapering toward their extremities. For optimum strength, such structuralmembers are cast with fiber or metal reinforcing bars (rebar) (12)emplaced vertically and horizontally as shown as shown to increase thestrength of the member in operation. Holes (14) are preferably formed inthe vertical wall and footer portions to provide drainage for liquidcollecting behind the retaining wall or seawall. Holes (16) can also beplaced to facilitate handling and temporary interconnection of theL-members as well as drainage.

The L-shaped members and other components disclosed herein can beprecast by conventional methods known in the art, and in some casesexisting commercial components can be utilized to assemble the novelshoreline reinforcement systems of the invention. When the componentsare to be exposed to salt water, it is preferred that all rebar be atleast about 2 inches from any surface of the cast bodies. Fiberreinforcement should be included in the concrete for strength, arelatively high proportion of Portland cement should be used in the mix,and the forms should permit a smooth finish to be obtained on thefinished molded objects. The forms should be subjected to vibration,using commercially available mechanisms, after the molds are filled toconsolidate the concrete and minimize voids or defects. Preferably, flyash and other recycled materials should be used in the concrete to theextent it is physically and economically beneficial.

FIG. 2 is a sectional view of an inverted T-shaped unit as disclosed inU.S. Pat. No. 5,697,052 FIG. 2 illustrates a cross-sectional view of aninverted “T” wall or structural member (50) as disclosed in U.S. Pat.No. 5,697,736, having a vertical wall (52) and a symmetric base orfooter (53). Such components can be cast of concrete, preferablycontaining rebar reinforcement (54) as illustrated above for the “L”walls, in various sizes and proportions to suit the application. Forexample, for shoreline reinforcement systems exposed to water, such “T”walls can range from about 2 to about 6 feet high and from 2 to about 6feet wide, the ratio of height to width of the base ranging from about0.6 to about 1:1. The sections can range from about 6 to about 16 feetin length. Particularly when the installed structures will be exposed totidal flows, strong currents, surf or pack ice, the width of the baseand the lowness of the center of gravity should be emphasized tominimize the risk of tipping. A plurality of holes (56) can be formed inthe wall to facilitate handling, some sand and water bypass andinterconnection. Similar holes in the base permit the use of pins,harpoon type anchors or stakes (58) to secure the units to the beach.

In the present systems, these inverted “T” walls are used to form groinsextending seaward from a seawall or bulkhead, and may optionally be usedin rows parallel with the seawall as well, as part of a system toreinforce the shoreline, form a “perched beach” or the like. Such groinsare typically installed substantially perpendicular to the seawall andare used in pairs or greater numbers. The spacing and length of suchgroins must be carefully selected to encourage sand, gravel and othermaterial to collect on the beach. In some cases the effects of groins,seawalls and other beach reinforcement systems can be difficult topredict even after careful analysis. If necessary, the “L” walls andinverted “T” walls described above can be disconnected and relocated.Such analyses are beyond the scope of the present disclosure, but someguidelines may be found in “Low Cost Shore Protection”, published by theU.S. Army Corps of Engineers.

FIG. 3 is a sectional view of a conventional “double T” or pi-shapedunit from U.S. Pat. No. 5,697,052. FIG. 3 illustrates in cross-sectionalview conventional “Double T” cast concrete structural members (66) whichmay be used in systems of the present invention. Such structural membersare used in constructing parking garages. The lengths of such units canrange from about 20 to about 60 feet, with length limited mainly by thedifficulties of handling such heavy components over the road and alongshorelines where they are to be installed. Because of their dimensions,the two tapered upright sections (68) joined to the flat base portion(69) give the appearance of two “T” shapes joined side-to-side. Theunits are also known as “pi” units because of their resemblance to theGreek letter pi.

FIG. 4 is a perspective view of a precast concrete box which wasdisclosed in the Veazey et al. patent for use in constructingbreakwaters and the like. As an alternative to arrangements of inverteddouble “T” units to form pier groins, precast concrete boxes of varioussizes can be used for various site-specific conditions. For instance,precast septic tank forms come in various sizes, e.g. approximately fivefeet wide by eight feet long and three feet depth, with walls fourinches thick. Concrete boxes made from these existing forms can be usedwith modifications of openings, stronger and more waterproof concrete,reinforcements, connecting devices and the like, being sunk in positionto form the base of pier-groins and the like and filled with water,rocks, sand or rubble. However, preferably they are adapted as shown inFIG. 4 and disclosed in U.S. Pat. No. 5,697,736, where the box (81) hasfour sides which have been perforated or slotted with circular holes(83) and/or rectangular slots (85) of a few inches diameter or width.This will make the boxes easier to sink and anchor in position. As withthe inverted T units shown in FIG. 2, the boxes can have holes formed inthe bottom to accommodate anchoring stakes of rebar, screw anchors suchas shown in FIG. 24 of the previous patent, or other suitable anchoringmeans. Preferably plugs are used in the casting molds to form holes (83)or slots (85) which are sealed by thin layers of concrete. Such holeswill also make it easier to sink the boxes in the water, as the thin“knockout” portions of the concrete can be punched out once the boxeshave been floated into position. Once sunk, of course, it is difficultto refloat such boxes.

Such perforated and/or slotted boxes can serve an additional functionbeyond anchoring the foundation of a pier groin or other component.Since waves striking the surfaces of such boxes will be partiallyinterrupted or deflected and partially absorbed by passage through atleast one side of the box (i.e., the perforations or slots), their forcewill be at least partially dissipated. The water inside the boxesremains largely restricted or “dead” during the time periods of thewaves. Thus, such boxes may be used as “wave degeneration cells” ascomponents of the foundations of pier-groins, groins parallel orperpendicular to the shoreline, or even breakwaters. The dimensions andarrangement of the boxes as well as the dimensions and locations oftheir perforations and/or slots are of course selected to suit expectedconditions. Additionally, these boxes with openings could also serve asprotected nurseries for baby fish, crabs, oysters, etc. Such boxes, andother precast concrete boxes described below, can also be used on thesea bed to support racks, baskets or other substrates above siltationlevels for shellfish to adhere and grow. Providing such elevatedshellfish beds may permit the shellfish to be placed at the optimumdepth of water to avoid pollution and siltation and obtain maximumbenefit from currents, sunlight and nutrients. The perforations and/orslots should not extend too close to the base, where they might hinderretention and/or accumulation of anchoring material.

Such a breakwater can be built by anchoring a linear array of theprecast concrete boxes so as to form a wall either, e.g., five or eightfeet wide, then stacking the units as shown in FIG. 4 and lashing orotherwise fastening them together to form a breakwater of suitableheight. At least the lower layer of the boxes should be at leastpartially filled with sand, rock or other anchoring material, butvacancies left in some of the boxes will provide shelter for marinelife, thanks to the perforations and/or slots which allow easy access.

FIG. 5 is a side view of an improved L-wall in accordance with thepresent invention. Reinforcing bars, drain holes, securing holes and thelike can be included as shown in FIG. 1, and are omitted here forclarity. Fillets (15) can be formed of concrete between wall (4) andfooter (6) (and/or splash plate (10) to increase the strength of theunit and provide more cover for the steel reinforcing bars. L-wall (2)is shown with vertical key (8) placed in a concrete culvert or “trench”(9) of various depths which has been dug, leveled and backfilled tofacilitate installation of the L-wall. Pipe (13) is cast into theportion of the L-wall between splash plate (10) and footer (6) toprovide a channel for pressurized water (or water-air mixtures) to beused for “jetting” the key (8) into place in sand and/or for flushingthe key trench. Only one pipe (13) is shown in this view, but a seriesof pipes are to be cast into the L-wall along its length to facilitatejetting the unit into the sand which has been cleared of rock anddebris. Any suitable arrangement of hoses and/or manifolds can be usedto introduce water and/or air through pipes (13) during “jetting in” theL-wall. Such “jetting in” procedures are described in columns 9/10 ofU.S. Pat. No. 5,697,736. Another series of pipes (11) are included intrench (9), also to assist in jetting the trench (9) into the sand.Expanded metal or heavy wire mesh is bent into lengths of rectangularreinforcement (17) which are open at one end and cast inside trench (9)to form a reinforcing structure.

Improved L-wall (2) is shown here with a precast concrete tip cap (20)placed atop the vertical or stem portion (4). Tip cap (20) is formedmuch like a household rain gutter, with sides (21) and bottom (23)defining channel (25), and is preferably cast in appropriate lengths tocover the entire length of the L-wall, although they can also be formedin shorter units. Among other uses, such caps (20) can be placed atop aseries of L-walls to hold the tops of their stems (4) in alignment. Alsoshown schematically with this improved L-wall (2) is a set of precastconcrete steps (22) cast with cap (20), a precast body incorporating aseries of right angles which can form steps when aligned with one sideof stem (4) of L-wall (2). The steps are braced on both sides by solidsidewall units (27) which are cast on each side of the step ends andcontact L-wall (2) on the seaward face, respectively, of stem (4) andsplash plate (10). Such a step installation can be conveniently used bypersons to climb to the top of the L-wall, which may form a portion of aseawall, bulkhead or the like. Such steps could be placed near theupstream or uncurrent side of a groin, where they would be covered bymore sand on the lower steps for stability.

FIG. 6 is a side view of another accessory for L-walls (2), namely aprecast concrete sidewalk cap 30 having a channel (32) formed therein tofit atop stem (4) of L-wall (2), a cantilever support (34) and a flatwalking surface (36) extending to one side of the unit. When L-wall (2)is built into a seawall or the like and the landward side is filled in,such sidewalk caps (30) can be installed atop the L-walls to provide aflat surface suitable for use as a sidewalk or the like. Furthermore,precast concrete terrace retaining walls (38), having a slightly taperedrectangular cross-section, can be cast into such a sidewalk cap (30) toextend the height of the L-walls. This is also convenient for forming alow wall separating a sidewalk or walkway from the seaward side of aseawall constructed of L-walls, if not backfilled. Optionally, retainingwalls (38) could be separately cast and mechanically attached tosidewalk cap 30. In addition to providing a flat surface atop a seawallor the like which can serve as a sidewalk, sidewalk cap (30) covers thearea immediately behind the L-wall to prevent scour from waves or rain.Terrace retaining walls (38) can be backfilled to provide retainingwalls atop sidewalk cap (30), or left freestanding as safety rails.

FIG. 7 shows a side view of the top of stem (4) of an L-wall (2) whichhas been topped with a railing cap (40). Railing cap (40) has abroadened lower end containing a channel (42) adapted to fit the top ofstem (4) (as with the sidewalk cap discussed above), and is secured inplace by slipping channel (42) over the top of stem (4). Cap (40) can bemechanically fastened to stem (4) by any suitable mechanical means, suchas pins or bolts (41) passing through holes (43) in both the base of cap(40) and stem (4). A cantilever section (45) can be added to cap (40),either cast integral therewith or attached by any suitable mechanicalmeans, to add strength and provide a narrow walkway landward of cap(40). As with the sidewalk caps, these railing caps can be fabricated invarious lengths, and can be used to keep the tops of the stems ofadjacent L-walls in alignment in addition to providing a railing orterrace wall atop an array of L-walls. Railing caps (40) can also befabricated in much shorter lengths or as posts (i.e., a foot or so inlength and width), with railings (not shown) inserted through holes (44)in adjacent units and mechanically secured in place. Optionally, forornamental and personal comfort purposes, an ornamental railing 46 canbe secured to the top of such railing caps by inserting mechanicalconnection strip (or pins) (48) into groove or holes (49) in the top ofrailing cap (40). Railings (46) can be made of materials such as wood,metal and polymeric compositions, preferably those which can be madesmooth to the touch and durable when exposed to the elements.

The sidewalk, terrace and railing caps described above can be precastconcrete as discussed in U.S. Pat. No. 5,697,736, and can be connectedtogether if desired, by mechanical devices also disclosed in thatpatent.

FIG. 8 shows a side view of the improved L-wall of FIG. 5, withadditional features. Holes (25) are included in the stem (4) of theL-wall during casting, to provide for drainage through the L-wall fromthe landward side to seaward. These holes can be plugged if necessary(e.g., when L-walls are used to form a dam or dike) with solid plugs(27) (formed of any durable polymer such as polyvinyl chloride), orhollow plugs retaining in place a filter cloth soil retainer (29).Filter cloth retainers (29) are used in lieu of a larger continuouspiece of filter cloth or geotechnical material to cover holes (25). Ifsuch filter cloth or geotechnical fabric should deteriorate over time,additional solid or hollow plugs could be inserted from the accessibleseaward side of the L-wall. Perforated metal or polymeric fittings (31)are cast into stem (4) and/or footer (6) at each end of the L-wall toprovide means for interconnecting the L-walls via bolts or othersuitable mechanical fasteners. Drain holes (14) can be left open orplugged with solid plugs (27) or hollow plugs with filter cloth, asdescribed above.

The improved L-walls of the present invention can incorporate theextended angular splash plates, disclosed in column (6) of U.S. Pat. No.5,697,736 and the figures cited, which are incorporated herein byreference.

FIG. 9 provides a top view of the stems (4) of two L-walls (2) which areto be fitted together. In A, the edge of the stem (4) at the right isbeveled so as to fit into a corresponding groove in the stem (4) on theleft, backed by filter cloth for drainage or filled with bead caulk (33)or other suitable material to be inserted between their surfaces toprovide a good seal between the two L-walls if used as a farm pond damor the like. The L-walls of the present invention can be cast with oneend of the stem beveled and the other grooved, as described, tofacilitate such fitting together during installation. At B, the stem (4)at right has a trapezoidal projection (37) which fits into acorresponding groove (39) in the other stem (4). Caulking material (33)can be used as in A. The C version uses a dovetail method, withprojection (41) and groove (43) in the two stems (4), to provide a moresecure fit. One L-wall must be lifted to join the two stems in thiscase, and caulking is optional.

FIGS. 10 to 12 are plan, side and end views of precast concrete boxes ofthe invention which can be employed on shorelines, underwater and inintertidal zones. The boxes (90) take the form of a simple hollow box ofrectangular parallelepiped form with sides, ends, bottom and open top,which can be optionally capped with a tight-fitting top (92), held inplace by gravity or optional mechanical fasteners (not shown here). Top(92) is omitted in Fig. (10) for clarity. Holes (94) are provided in thelower corners of the sides and ends to be used for connecting cables orrods (not shown here). Vertical holes (96) are provided in each cornerof the box at the top to assist in securing top (92) when used or formechanical connecting devices when the boxes are stacked or secured tothe bottom. A low sill (98) on the inside bottom divides the box intohalves for connecting overlapping boxes alongside, and holes (99) extendlaterally from side to side through this sill to accommodate connectingdevices such as cables or rods and also handling means. The boxes shownhere are intended to be fluid tight (when capped), in contrast to theboxes of FIG. 4, which are open to the water in which they are immersed.The boxes can be positioned adjacent each other (side-by-side and/orend-to-end) and fastened together using holes (94), (96) and (99) andvarious mechanical fasteners. When interconnected side-by-side, theboxes are preferably positioned in overlapping fashion (with the ends oftwo boxes positioned adjacent the center of a third box) to form astronger structure. These boxes can also be stacked as shown in FIG. 4.

Conventional metal shipping containers can be used in place of or inaddition to precast concrete boxes in forming the shoreline structuresof the invention, with slight modifications. Such modifications areillustrated in FIG. 66. The shipping containers 82 normally have smallvent holes 84 approximately ½ inch diameter in a plate approximately1″×2″ in each upper corner on opposite sides 86 of the container, oneforward and one aft. The access doors (not visible here) are in one endonly. The arrangement in a line could be such that the access doorscould be on the ends for access to check the internal condition when inthe water or for storage underwater. Alternatively, with the door accessfacing inboard and doors therefore blocked by the adjacent container,the potential for damage or accidents would be reduced.

In cases where older or damaged shipping containers do not seal well atthe doors, or are not airtight, an accessible door can be opened and alarge elastic air bladder (such as fuel bladders widely used in themilitary) inserted. With the neck of the bladder extending through a tophole in the container, the bladder can be inflated and sealed to floatthe container for removal or relocation.

To easily install flood and drain openings, short lengths of steel pipecan be inserted and welded into holes 87 cut into the steel side of thebox near the bottom 88. The size of the inside diameter (ID) of the pipeis such that it is the same that would accept standard plugs or valves.For instance the pipe could accept 4″ plumbers' plugs in a 4″ ID pipe.

The blow and vent valves could be installed in at least one hole 89 onthe sidewall 86 near the container top 91 or on the top itself. Ineither case the valve and/or plug as well as the pipe should extend moreon the inside than protruding externally so as not to interfere with thestacking of the units one above the other or side by side on a containership for transport.

A quick-connect valve such as disclosed in FIG. 30 of Applicant'searlier U.S. Pat. No. 6,491,473 (not shown here) can then be insertedinto the pipe just as in an opening lined with pipe cast into a similarsized precast concrete module having the form of a regularparallelepiped. Suitable mechanical connections are added to the edgesand/or corners of the boxes for interconnection, as disclosed herein forthe precast concrete boxes.

These boxes and those described below are preferably “intermodal” shapeswhich can be conveniently handled and shipped by at least two modes oftransportation, including trucking, railcar and surface watertransportation including container ships and barges. That is, they havedimensions (length, width, height) which will permit them toconveniently fit into the allowable spaces in such transport media,either singly or in combination. For example, currently standardcontainers measuring approximately eight feet wide by 8.5 feet high andeither twenty or forty feet long can be easily transported by ship, railand trucks. Furthermore, these boxes can be produced as sets of at leasttwo different sizes, having proportional dimensions which facilitatetheir use in standard size transportation media and together to formstructures such as seawalls and other shoreline reinforcing systems ofvarious sizes.

For example, FIGS. 13A, 13B and 13C provide top, side and right end andplan views, respectively, of boxes of several dimensions positioned ondeck for transport in a space forty feet long and 24 feet wide, withboxes stacked to a uniform height of about 8.5 feet. The dimensions ofboxes of types A through H are indicated in the legend. Clearly, whereboxes having dimensions as large as about eight feet square by fortyfeet long can be conveniently transported, a number of boxes having atleast one dimension a suitable fraction (e.g., one half) of these can beassembled to fill the same space for transport within frames. Thus, foran intermodal set of boxes, the maximum dimensions are determined by themaximum space available on deck and/or inside a truck trailer orrailcar, and smaller boxes can be designed with similar proportions buthaving at least one dimension which is, e.g., one half or one third ofthose of the largest box of the set. In other words, the smaller boxesare produced with one, two or three dimensions which are a fraction(preferably divided by a whole number) of the corresponding dimensionsof the largest box of the set, which may be described as the “master”box.

Similarly, FIGS. 14A (left end) and 14B (plan view) illustrate the useof boxes selected from those of FIGS. 13A and 13B to form a structureunder the surface (306) of the water. Two “C” boxes with innerpartitions (98) are positioned end-to-end, and are overlapped by box“D”. Two “E” boxes are similarly placed, with their midpointsoverlapping the junctions of the “C” boxes. Pairs of boxes can beinterconnected by mechanical fasteners (99).

FIG. 15 is a top view of an improved version of the box (90) of FIGS.10-12, with a partition wall (102) dividing the box (101) into halves101A and 101B. The box has the general shape of a rectangularparallelepiped, with certain preferred ratios of dimensions which arediscussed above. Vertical, horizontal and longitudinal sections ofconduit are cast into the walls to form holes (96) in the corners andmidpoints of the walls. These formed pipes can be used for reinforcement(shown as 97), lifter and stacking attachment points and post tensioncables or conduits for wires or fluids when used as building modules.Slab tops (92) (not shown here, but similar to those of FIGS. 11/12) canbe used to seal the boxes. Alternatively, such boxes could be cast intwo halves, either top and bottom or front and back portions.Pressurized fluid (water and/or air) could support an internalexpendable lightweight form to support the wet concrete being cast atopthe cured bottom half to create a unitized watertight structure. Floodand drain holes (108) pass through the sides of box half 101A forflooding or draining, as discussed below, and are protected by internalgrates (130).

FIGS. 16 and 17 are side and end views of an improved box (101), similarto box (101) of FIG. 15, illustrating devices for flooding and blowingthe box when in the water, and for fastening such boxes together to forma structure. The boxes are completely enclosed, including a solid top ortop half bolted and sealed with gaskets, elastomeric sealants or othersuitable sealing means. Cables (106) are connected to the left side ofbox 101 through holes 118 in the corners and tensioned to compress aline of boxes together, and are also connected to the adjacent box in anarray thereof. Resilient cushioning materials such as used tires (104)are preferably suspended from cables (106) between the boxes to minimizeimpact damage where desired. Such cushioning materials should be placedat each corner between adjacent boxes.

FIG. 17 is an end view illustrating the placement of such tires, usingholes (118) in the corners of the box. Flood/drain holes (108) (shown asone method for 101A) at the bottoms of the sides of the box half 101Aare penetrated by knocking out a thinner casting of concrete should thebox need to be flooded and sunk or later blown and surfaced. These holesare protected by inner grates (130) to keep out gravel, etc. Valveassembly (112) with an expandable washer which seals inside against airpressure, an example of which is shown inserted as (112A), is held inplace in blow and vent hole (109), and sealed by a flexible “bayonet”anchor washer (113). An expandable and threaded quick connect blowfitting (shown in FIG. 30) is an alternative. Holes (115) penetrate thereinforced section adjacent to partition wall (102), and can beunplugged and fitted with pipe snap-in connections (116). To flood thebox, hose (117) can be attached to the discharge of a pump or insertedinto the sea and used as a siphon with hole (108) open, or alternativelyinserted in valve (112A) open as a vent. To deballast water, this isused if the flood/drain holes (108) are intact and are covered byaccreted sand. Also, these holes (115) can be interconnected to equalizepressures between the two sections of the boxes to float level. One endonly could be deballasted to raise that end and break the bottom suctionforces to surface the box. Alternative flood/drain holes (119) can beincluded in the bottoms of the boxes, with external plugs which could beuncovered and removed to permit deballasting. The box can be made tofloat unevenly if needed by partially flooding the portion at the end tobe deeper.

FIGS. 18 to 20 illustrate a method of floating single compartment boxesinto position and sinking them in place for installation. FIG. 18 is aside view of a box (101) floating near the surface of a body of water(120). Box (101) can be attached to a similar box via cables (106)attached at the corners or passing through holes (118) at the corners(only partially shown for clarity). High pressure blow/vent valves (126)(similar to valve 112 in FIG. 16) are fitted to the top of box (101). Asan addition, a septum with an air pipe or simply an air pipe (122) withvalve (124) can be used to break suction, and air can be ejected throughthe bottom at (128). Grated flood/drain check valves (131) are fittedwith rubber flapper covers (132) which close after the box has sunk tothe bottom to prevent sand entry, but open when air pressure forceswater out of the box for deballasting.

As shown in FIG. 19, several boxes (101) can be interconnected to forman array, with cables (106) and tires (104) between adjacent boxes.Alternatively, larger cushioning materials (134), such as an inflatablefender, rope fender or the like, can be employed. In operation, a singlebox (101) or an array thereof (FIG. 19) is placed in the body of waternear the proposed underwater or tidal installation and moved intoposition. The box or array can be pushed or towed by tugboats, smallboats or any other suitable force. Once in position directly above theproposed installation site, the box or boxes are sunk in place byopening vent valves (126). Hydraulic or electrically operated valves,actuated by suitable signals conveyed by electrical, acoustic or optical(i.e., fiber optics) means, can be opened sequentially for a controlledand coordinated sinking of the boxes. The box or array will normallyrequire some longitudinal restraint or guidance, such as anchors, toensure that it sinks into the desired spot. Lines tended by anchoredboats or divers should suffice for side-to-side alignment of the boxes.Alternatively, anchors and small craft or tugs can be used, asillustrated in FIGS. 46-48.

FIG. 20 is a side view of a box (101) which has been sunk in body ofwater (120) to rest upon the bottom (131). Rock, gravel, sand and othermaterials can be added in and around the structure to create great massinside (if (101) is an open box) and a higher sea bottom around the boxor array thereof, as indicated at (133), and with time and tide,additional sand, silt or other materials may collect around thestructure to create an even higher bottom surface, as at (135). Alsoshown in FIG. 20 is a pipe or tube (136) extending from top to bottom ofbox (101), providing an alternative method of flooding and draining thebox. Air can be vented through valve (126) while water is siphoned intoor is pumped in through pipe (136) to initiate flooding of the box,until pipe (136) is submerged when air venting through valve (126) willsuck water in through pipe (135). Suction can be applied tosubstantially drain the box when needed, with air admitted through ahose, or while air under pressure through valve (126) will also do thejob. Pipe (136) is permanently installed or can be inserted throughunplugged precast holes.

FIGS. 21, 22 and 23 illustrate the use of anti-scour plates inconjunction with the boxes of the invention. As described for theL-walls of the invention in U.S. Pat. No. 5,697,736 at columns 5/6,waterfront structures subject to waves, tidal action or storms mayrequire devices to prevent water from “scouring” or eroding the beachmaterial from under the seaward edge of the structure. FIG. 21 is a planview showing anti-scour plates (140) attached to both sides of box (100)at the lower edges by mechanical means (142) such as hinges, hooks,rings, cables or the like. When both sides of a box incorporated in awaterfront structure are exposed to water, anti-scour plates on bothsides may be required, as seen in FIG. 21. As shown in FIG. 22, wheninstalling box (100), anti-scour plate (140) can be lowered into aposition to contact the beach or underwater bottom surface beside thebox. Prior to installation, anti-scour plate(s) (140) can be retained inplace against the sides of box (100) by suitable mechanical means suchas lockable lashing eyes (170) (shown in FIG. 25). As shown in FIG. 23,the anti-scour plates (140) can be raised or lowered into position byany suitable mechanical means, e.g. using cables (146) attached toattachment points (144) and winch (148) (or other hoisting means). Oncelowered to contact the beach surface, such anti-scour plates may becovered by deposited sand and gravel or scoured and lowered to aposition of stable equilibrium and embed themselves in the beach orunderwater bottom surface to prevent water from removing beach materialfrom under the edge of the box. Such anti-scour plates can be formedfrom precast concrete, corrosion-resistant metals, geotextile materials,polymer composites, or any suitable material which has the requiredproperties of stiffness and durability. The boxes can be shipped withanti-scour plates attached, or the components can be shipped separately.

FIGS. 24 and 25 illustrate mechanical attachment means which can be usedto fasten such anti-scour plates to the boxes. FIG. 24 is a perspectiveview of a commercially available “twistlock stacker” (150) used tointerconnect containers on container ships. These units include lockingplate (158), attached to body (160). Handle (154) is used to manuallyrotate locking plate 158. To form a hinge, a large bolt (153) can beinserted through eye (155) of one unit (on top 156) and through the eyeof a similar unit. The hinge is suitable for one-time uses, as insecuring anti-scour plates to boxes.

FIG. 25 is a perspective view of two D-ring lockable lashing eye units(170), having D-rings (178) attached to D-ring hinge (176), which can beattached to boxes (100) by divers, or on the ship before offloading, andlinked by mechanical means including chains, U-bolts or detachable links(180), closed by nut (182), to form a hinged attachment of theanti-scour plates to the boxes. The units can include lock (172), andthe D-rings (178) are attached to plate (174). Such fittings arecommercially available from many marine supply houses.

FIGS. 26 to 29 illustrate methods of attaching adjacent boxes (100)and/or (101) together to form arrays. FIG. 26 is a side view of twoadjacent boxes (100), each having a locking plate receptacle (180) castinto the corner of the concrete box and anchored by steel connectorssuch as reinforcing bars (182). Such units consist of a hollow metal boxwith a smaller racetrack opening (185) embedded in the concrete toreceive locking plate (186) of a twist lock inserted through opening(185) and twisted with lashing eye (189). Chains, cables, turnbuckles orother suitable mechanical connecting means (not shown here, for clarity)can be fastened to locking plate (186) to connect the boxes. Theseconnecting means can be used in lieu of or in addition to tensionedcables (106) (see FIGS. 16, 18, 19) for interconnecting the boxes. Suchconnecting means can be connected onboard the ship or barge beforeoffloading, or by divers on the bottom.

FIG. 27 is a side view of two boxes (100) held together by adifferential screw (190) and cushioned by used tire (104) or the like.Female twist-lock locking plate receptacles (180) which are welded toreinforcing bar and cast into the concrete box (same as in FIG. 26)contain an oval or oblong lip and recessed larger opening underneath.Nuts (188) are included and attached pivotally to locking plate (186)through which differential screw (190) can be threaded through atwist-lock lug (188) to fasten the boxes together. Holes (187) inlocking plate (186) provide recesses for a tool to apply torque to thelock. Fittings (192) for a power-driven drill socket are provided totighten differential screw (190) and produce the desired spacing of theboxes and screw tension.

FIG. 28 is a side view of a simpler connecting system in which boxes(100) are fastened together by a turnbuckle (200) connecting recesses(187) in bases (184). Many standard commercial turnbuckles can be used,with hooks (206) of turnbuckle screws (202) inserted into recesses (187)and tightened by rotating turnbuckle screw (204).

FIG. 29 is a side view of two boxes (100) having recesses (187) in bases(184) installed in each corner, which are to be connected by a strongmetal plate (210) (or the like) and two twistlock stackers (212), shownschematically in perspective as attached to the plate. The boxes areconnected simply by positioning them the correct distance apart andinserting and tightening twistlock stackers (212) (shown in detail inFIG. 24) into recesses (187) and locking them therein.

FIG. 30 is a sectional view of a quick-connect fitting (220) insertedthrough a hole (254) in box (100) or (101) (formed by pipe (244) cast inplace or placed in hole 254) for venting and blowing. A hole (254) ismolded or otherwise formed in the wall, top or bottom of box (101), andis lined with or cast with a polymeric pipe insert (244) which is formedof polyvinyl chloride, another suitable polymer or other suitablematerial. Grooves (240) in the outer surface of insert (244) will retainpart of the wet concrete and bond the insert to the concrete hole ifinserted during molding. Grooves (241) on the inner surface of pipeinsert (244) can be fitted with elastomeric O-rings (243) to provide aseal between pipe insert (244) and locking fitting (230). A larger tightO-ring (242) fits in groove (245) to provide a force to squeeze lockingarms (234) of the locking fitting (230) inward to allow a fit into pipeinsert (244).

Locking fitting (230) is fitted with top flange (232) and flexiblelocking arms (234). Additional O-rings (238) are fitted between topflange (232) of locking fitting (230) and the concrete wall of box (101)and pipe insert (244). Locking fitting (230) is formed so that the upperportion of its inner aperture is threaded (256) and the lower portion ofthis aperture has a smaller diameter than the threaded upper portion.This allows unthreaded cylinder (229) to fit through locking fitting(230). Inner spreader insert (222) has a top hexagonal flange (224) andis externally threaded (226) to be screwed into threaded aperture (256)of locking fitting (230). Inner spreader insert (222) has a lower,unthreaded cylinder (229) which contacts the tapered insides of thelocking arms (234) of locking fitting (230) when it is screwed in andspreads the locking arms (234) to contact pipe insert (244) with a camaction to lock and compress O-rings (238). With the quick-connectfitting secured and sealed to box (100) or (101), an air line withshutoff valve (not shown) can be inserted into hole (228) and lockedinto groove (259) to form a quick connect coupling to permit air to blowthe water ballast out of the box or connect to vent valve to contain airto float the box or release air to permit flooding and sinking.

FIGS. 31 to 33 illustrate the use of such concrete boxes to construct awaterfront boathouse. Plan view FIG. 32 (without roof deck (314) forclarity) shows three or more concrete boxes (103) of suitable size andproportions assembled open side up, optionally fitted with concrete orwooden tops (e.g., as shown in FIG. 12) upon the bottom (304) of ashallow harbor or other body of water (306) in a U-shaped configurationforming a mooring area 308 to shelter a boat (310). The upper surfacesof the boxes (103) can be fitted with standard mooring fixtures and thelike (not shown here), and allow passengers to easily embark and debarkon or from the boat. Boats may be moored on the outer sides of theboathouse as well, if desired. As shown in end view FIG. 31, boxes (103)are higher than the depth of water (306), but for deeper water orlocations where minor tides occur, boxes (103) can be stacked two ormore layers deep to provide an upper surface which will lie above thehighest normal water level. Holes (302) are provided in the closedbottoms and/or tops of boxes (103), or alternatively outside of theboxes, to accommodate pilings (312), which are driven into bottom (304)to retain boxes (103) in place. The boxes can also be interconnected bymechanical means, as discussed above.

The pilings are hollow tubes of metal or plastic pipe, which are filledwith concrete when all boxes and pilings are in place to providepermanent structural strength. Since the main strength is provided bythe concrete thus cast, the material for the pipes is not critical, butthey are preferably made of durable plastic materials such as PVC sothat they will not corrode. The boathouse structure here is emplacedwith the closed end toward the shore (with normal walkways or the likeprovided for access, but not shown here) and the open end toward thewater for boat access. The closed end of the boathouse is shown in FIG.31.

Optionally, a roofdeck (314) can be provided, comprising a solid deck(316) perched atop pilings (312) and secured in place mechanically. Deck(316) can also be of precast concrete of suitable thickness such asprecast sections spanning the distance between pilings (312) and anynecessary supports, wood, recycled plastic “lumber” or any suitablebuilding material. Preferably roofdeck (314) includes an open railing(318) suspended from posts (319) for safety, and is provided with accessby stairs or ladders (not shown) for use by the owners. Movable or fixedside curtains or other closures such as fixed walls (not shown) can beprovided for privacy and protection of boats using the structure.

Since such a structure with completely solid sides underwater could bevulnerable to scouring and forces exerted by local currents, as shown inFIG. 33, arched passages (320) and/or pipes or culverts (321) are castor cut into the sides of boxes (103), extending approximately as high asthe expected water level (306), to allow any currents to flow through asindicated by arrows in FIGS. 31 and 32. These boxes are preferably castwith a solid surface extending along arch (320) to provide a bottom ofthe box to hold sand which can be added for ballast. A flat bottom canalso be included to spread the weight of the structure over a largerarea, and the structure can also be mechanically attached to piles (312)for support to prevent settling.

FIGS. 34 and 35 are open end and plan views of a floating boathouse(400) employing enclosed boxes (103) of the invention. Boxes (103) areagain assembled to form a U-shaped structure to accommodate a boat (310)therein. The boxes are interconnected by suitable cables or connectorsas shown in FIGS. 26, 27 and 28. Boxes (103) float in water (306)adjacent to shoreline (402). The boxes can be completely precast orenclosed by adding precast concrete covers as described in FIGS. 11/12or decks of wood, recycled plastic lumber or the like. To help the boxesto float, they can be sealed to retain air, can be compartmented asshown in FIG. 15 and/or filled with foam, ping-pong balls, Styrofoampacking materials or other buoyant materials. Intermodal-sized boxeswhich measure eight feet square by forty feet long can conveniently beused. Boathouse walls (404) are erected upon the upper decks of boxes103 to form a boathouse structure thereon. Walls (404) are preferablystrong weight-bearing solid walls (using suitable construction materialsdiscussed above) to support an optional deck (314) as described above,but can be cut out to form windows, doors, etc. Roof deck (316) supportsrails (318) supported by posts (319). Beams (406) extend from the innerupper edges of boxes (103) to the lower surface of roof deck (316) toincrease strength and rigidity.

The top decks of boxes (103) can be fitted with appropriate mooringfixtures for boat (310) (not shown here), allowing mooring both insideand outside the walls. The boathouse itself can be secured to bottom(304) by standard mooring systems such as a four point moor, chains(410) to clump anchor (412), or screw anchors (413). The boathouse canalso be retained in place by a number of piles (105) passing throughrings or brackets (107) which are attached to the sides of boxes (103).Ramp (408) or other suitable means can be used to provide access fromthe deck of box (103) to boat (310). Similarly, optional pier or walkway(410) connects the floating boathouse to land (402). Two or more rigidspacing bars (315) are provided between the arrays of boxes andmechanically attached at (317) to keep them in alignment. This boathousedesign can provide a relocatable, permanent or temporary facility forpilots, marine patrols, military forces, Coast Guard, and the like.

FIGS. 36 and 37 (plan and side views) illustrate a standard fixedboathouse design (420) with a series of concrete boxes (103) addedaround the supporting piles (311) to protect them from ice and storms byadding mass to the structure and deflecting floating objects. The pilescan be any conventional type of wood, metal or concrete, or pipe filledwith concrete as discussed in FIGS. 31-33. The concrete boxes which areplaced about the piles are precast concrete boxes as described above,which can have either closed or perforated sides, and are approximatelysquare in cross-section, preferably being approximately cubical. Thepiles are inserted through holes placed in the bottoms (and tops, ifpresent) of the boxes, which are stacked in the positions where thepiles are to be driven. Once the piles are driven and the boxes filledwith water and sand or gravel, the assemblies form a support for theboathouse (or other structure) that is almost impervious to floating iceor other debris, waves or currents. The boxes are stacked andinterconnected by methods discussed above. Such precast concretestructures extending from the bottom to the waterline or higher can beemployed to protect various types of waterfront structures, such asdecks, mills, dam or power plant components and the like. Lifts (423)can be provided to lift boats out of the water.

FIGS. 38 to 40 illustrate a precast concrete “bridge box” 450 which is along, flat rectangular parallelepiped in form, including ahemispherical, round, rectangular or oval cutout portion (452) in bothof the longer sides. The box can be closed on all sides except where cutout, or can be open on the bottom below cutout (452). Preferably the boxis cast with a solid bottom along cutout portion (452), to retain sandwhich may be added via suitable inlets for ballast. Alternatively, pipes(453) of appropriate number and size can be cast into an otherwisecompletely enclosed bridge box. FIG. 38 is a side view of a singlebridge box (450), while FIG. 39 is a top view of a bridge (454)assembled from three boxes (450) placed side by side to form a roadbedor path, cutouts (452) coinciding to form a culvert (455) for a streamor other running water to pass under.

FIG. 40 is an end view of the bridge (454) of FIG. 39, showing a waterflow (456) through the culvert. Preferably concrete anti-scour plates(458) are fitted by hinges (457) on both sides of boxes (450) to protectthe lower edges where water flows through the culvert. Additionally,large or small pipes (459) and (460) cast into the boxes as conduitsprovide ready-made and protected means for installing utility lines.Such bridges or structures can be incorporated into shorelinereinforcement systems constructed in accordance with the invention. Theycan also be used to construct structures requiring bases which willaccommodate water flow, such as the boathouse illustrated in FIGS.31-33. This bridge box structure and method could provide for muchcheaper and faster construction of bridges, addition of traffic lanes,or replacement of old bridges over small streams and rivers. They couldalso be post tensioned over a wider stream or marsh. This design couldalso be used as a box penetration for storm water to pass frombeachfront roads through “boardwalk” boxes and berm boxes to allow stormwater to flow to the sea.

FIGS. 41 and 42 illustrate a shoreline reinforcement system constructedprimarily of precast concrete boxes in accordance with the invention. Inform and effect, this system resembles the systems disclosed in U.S.Pat. No. 5,697,736 in columns 11/12 and FIGS. 18/19. FIG. 41, the planview, shows an array of boxes of various sizes assembled along theshoreline to form a seawall and a “backbone” structure for a berm orsand dune seaward of the seawall. These boxes, in suitable sizes andproportions and numbered (501), (502) and (503), will generally beinstalled by heavy equipment such as cranes or tracked excavators,either from seaward or shoreward, and are filled with sand to providepermanent ballast. They can then be topped with permanent precastconcrete covers if desired to form a walkway atop the seawall andprevent scour of the fill inside the box. These boxes can be describedas “boardwalk boxes” (501) and are described in detail and illustratedin FIGS. 10-12. The boxes can take the form of rectangularparallepipeds, typically about eight to twelve feet wide by twenty toforty feet long by eight to twelve feet high, or can be nearly cubicalunits half that long. The large boxes (501) shown are segmented (withpartitions 102) and can be about eight to twelve feet square by fortyfeet long. Using boxes in at least two lengths facilitates theirinstallation in lengths suitable for the construction site and localconditions. Also, as described above, it is convenient for shipping touse intermodal units having lengths of ten, twenty or forty feet.

Extending laterally down the beach from the seawall are at least twoarrays of “berm boxes” (502), which can be about four to eight feet highby eight feet wide by twenty feet long, to provide berm groins andclosed berm cells (504) much like those employed in the systems in thepatent cited. Smaller box groins (503) form open groin cells (505).These may be open boxes which are filled with sand and then fitted withtops, or if local tidal conditions permit, can be floatable boxes whichare floated into position and then sunk in place, as described above.Another lateral row of berm boxes (502) is installed perpendicular tothe berm groins and approximately parallel to the seawall, filled withsand and left open or covered. The beach spaces between the berm groinsand lateral rows of boxes are partially filled with sand and preferablycovered with filter cloth and articulated concrete mats as disclosed inthe patent cited, in columns 10/11 and FIGS. 16/17, then covered withmore sand.

Alternatively, the spaces can simply be partially filled with gravel,rip-rap and/or sand, and local winds, tides and waves allowed to depositadditional sand, etc. with time. The result will be a stable structurethat prevents erosion of the shoreline and actually tends to build upsand and gravel to form additional beach under most conditions. Stormprotection is also provided for the boardwalk (or seawall) boxes and thelandward buildings and other structures.

Additional smaller groins (503) can be added to seaward of the lowerlateral row of boxes described above. Such groins (503) can be formed ofarrays of at least one “beach box” (503) (which can be about four feetwide by four feet or 2′ 8″ to 4 feet high and ten or twenty feet long)at the right and left sides, as described above for the berm boxes, andfilled with sand or gravel for ballast. Such boxes are preferably setfrom the land, or if intended to extend into the sea, floated intoposition and sunk in place for installation. In addition, or as analternative, T-walls (506) and beveled T-walls (507) can be used asshown in the center and described in the patent cited, in column 7 andFIGS. 8, 9 and 18. Such T-walls could be used for the entire pier-groinsas disclosed in the patent cited, or simply to provide the seawardcomponents of this system (in which case the beveled ends of the outwardT-walls minimize potential damage to boats and the like which approachclosely). In general, with no beach existing, it will be easier toinstall beach boxes where they can be floated into position, so they arepreferred for most components of the systems of the present invention.With an established beach, installation from landward is preferred. Thedouble T or “pi” units of FIG. 3 can also be used as components of suchshoreline systems, arranged parallel and/or perpendicular to theshoreline.

FIG. 42 shows the system of FIG. 41 in side view, the entire structurelying above mean high water, and the level of sand expected to build upafter storms and after renourishing by normal tidal action or byartificial methods. This system can be installed before renourishing aneroded beach to retain a large percentage of the new sand, which mightotherwise be washed out to sea during a storm. Even if some of thesacrificial sand is lost, these massive interconnected boxes and otherstructures are not easily moved by storm waves. However, if necessary,the boxes can be disconnected and relocated, using suitable heavyequipment.

Further uses of rectangular boxes (optionally in combination withhexagonal and half-hexagonal boxes), whether metal, precast concrete orfabricated of other materials, are illustrated in FIGS. 67 and 68. Oncea breakwater has been installed, with or without a groin installed fromthe middle of the breakwater perpendicular to the shore, a pier can beinstalled over the top of the breakwater. First the piles are installedover the breakwater boxes, preferably at the junctions of the boxes. Ifthere is a groin, then the piles are installed on either side from theshore out to the breakwater. Next the structure of the “T”-head pier asillustrated in FIG. 68 and the deck are built.

FIG. 67 shows a breakwater-groin assembly 970 comprising a breakwater971 formed of at least one layer of rectangular boxes 100 with open topsand an optional extension 972 connected to breakwater 971 and extendingshoreward. A groin 742 connects the breakwater 971 to shore 402 and alsocomprises rectangular boxes 100 with open tops. Boxes of various sizesand proportions, preferably of intermodal sizes as discussed above, canbe used, and can be fabricated of any suitable materials includingmetal, plastics and precast concrete, the latter being preferred forpermanent installations. Hexagonal boxes can be used to form at leastportions of the breakwater and groin, optionally in combination withhalf-hexagonal boxes to form flush outer surfaces where desired.Especially with permanent installations, as shown in FIG. 68, at leastone layer of solid materials such as concrete, wood or plastic deckingcan be installed atop at least of portion of groin 742 to providewalking surface(s) 36 and convert groin 742 and/or breakwater 971 topiers 758. Piles 312 are used to install and secure this surface layerand to provide moorings for small boats.

There are several mutual benefits from this arrangement. First, thepiles notify any boater of the location of the breakwater during astorm's high water or flood. Secondly, the piles help maintain the boxesin place before sand has built up to secure them in place. Also,initially the boxes are filled with water, which is lighter than thesand and silt that will eventually replace some of the water. As highstorm tides overtop the boxes and deposit some of the suspended sand,the mass in the boxes increases, thereby increasing the stability of thebreakwater. Thirdly, the mass of the boxes protects the pier from ice,large floating debris and hurricane strength storms.

The breakwater (and groin if installed) protect the land from erosion bynaturally building a beach. Boats can make landings and moor on theseaward side of the breakwater, whereas this would be impossible with astone breakwater. Additionally, smaller boats can be moored on theprotected landward side of the breakwater near the ends where the wateris deeper. Hence this combination yields not only preservation of land,but optimum utilization for land-water access.

Environmentally, the arrangement has benefits as well. Sub-aquaticvegetation will grow inside the boxes, where the box provides aprotective nursery from the storm waves crashing on the beach. Barnaclesand other plant material will grow on the inside, and crabs and fishhave access through holes in the boxes to find sanctuary from theirpredators. The inside bottoms of the boxes form ecosystems of their ownto replace a large percentage of the sub-aquatic river or sea bottomcovered by the outside bottoms of the box covers. Finally, in an actualinstallation on the Potomac River, it has been found that large massesof sub-aquatic vegetation are taking up residence outside the boxesbetween the breakwater and the land in the calm water provided by thebreakwater.

FIGS. 43 to 45 illustrate a novel vessel (570) and method fortransporting and installing precast concrete boxes of the invention tolocations for installation to form shoreline structures, breakwaters andthe like. Plan view FIG. 43 and side view FIG. 44 show a vessel (570)comprising two portions, bow (558) and stern (552), fastened tomidsection (562). Stern portion (552) comprises the conventionalpropulsion system (not shown), at least one propeller (554) and pilothouse (556) with appropriate controls. “Thruster” type propulsionunit(s) (559) can also be provided to improve maneuvering. Bow (558)comprises storage spaces for supplies, at least one anchor (not shownhere) and a crane unit (560). Both sections have flat vertical surfacescomprising primarily watertight bulkheads with a minimum of openingswhich can be secured to permit them to float independently. Bow (558)and stern (552) can be fastened together as shown in side view FIG. 45to form vessel (550) and secured by appropriate mechanical means such aslarger twistlock stackers (as shown in FIG. 28), turnbuckle locks,bolts, cam locks and the like. Thus secured, vessel (550) can travelunder its own power to a port where a stacked and securelyinterconnected floating array of precast concrete boxes of the inventioncan be attached between the bow and stern sections as a midsection forthe vessel for transportation.

As shown in FIG. 44, a large group of such boxes (101) can be stackedand grouped together to form a box module (562), which is fastenedtogether under longitudinal and lateral tension by a tensioning systemcomprising, e.g., corners (564) and (566) and cables (568). Similarlocking connections on the corner plates permit the array of boxes to besecured to the bow and stern sections of the vessel. Once assembled, boxmodule (562) is moved from an onshore assembly site (e.g. on a pier,wharf or ramp) by large crane or other suitable means into the harborwaters and floated into deeper water alongside a pier or within theharbor where the vessel may freely enter. Such a module can bemaneuvered around such restricted waters using mini-tugs (e.g.,converted military landing craft) or other suitable small craft andsuitable attachment points which are provided on the outside surfaces ofthe module (not shown here).

With the module held in place by such tugs, anchored or moored to buoys,vessel (550) can be brought alongside, bow section (558) detached fromstern section (552) and the stern section maneuvered against the rearsurface of the module (562), using propeller (554), thruster propulsion(559) or tug assistance if necessary. Contemporaneously, tugs or othercraft hold bow section (558) in position until stern section (552) isattached to module (562). The vessel's anchor can be used to anchor bowsection (558) during this period if desired, provided that an auxiliarypower source is provided to power the anchor windlass. Then bow section(558) is maneuvered into position against the front surface of module(562) by tugs and secured in place. The same systems used to fasten thebow and stern sections of the vessel together can be used to attach thebow and stern sections to the array (562) of boxes. The result is a“stretched” vessel (570) (shown in FIGS. 43 and 45 assembled, FIG. 44 indisassembled state) which can travel under its own power to the locationwhere the boxes are to be disassembled and/or installed.

In addition to transporting and unloading such floating arrays ofconcrete boxes as described above, the vessel of the invention can beused to carry a variety of other floating objects or arrays of objects,provided they are sufficiently buoyant, have appropriate proportions andcan be fitted with attachment devices to attach them securely to the twohull sections of the vessel. Various types of containers and tanks,floating bridges, pontoons, caissons and other floating constructioncomponents can be incorporated in the vessel and transported. This couldbe of particular value when transporting and installing components toform structures in areas of military landings. Furthermore, such avessel could be constructed to have the appropriate size, proportionsand attachment fittings to transport floating drydocks, whethercommercial or military. Floating drydocks are described in The NavalInstitute Guide to Ships and Aircraft of the U.S. Fleet, published inannual editions by the U.S. Naval Institute of Annapolis, Md. Most U.S.Navy floating drydocks are open-ended “through-deck” models, except forthe ARD models, which have one end closed by a ship-shaped bowstructure. The larger Navy models are sectional, allowing disassemblyfor easier towing. Some navy floating drydocks are on lease to civiliansalvage firms.

A representative floating drydock is shown in FIG. 64. FIG. 64illustrates a floating dry dock 820 comprising bottom pontoons 826 (Thelower hull portions of floating drydocks are typically referred to as“pontoons,” whether flush or protruding from the outer boundaries) withprotruding portions or sponsons 824, side or “wing” walls 822, gates828, interior bottom 829 and a crane 830. This particular floatingdrydock has a bottom fabricated of a series of floating pontoons 826arranged transverse to what would normally be the keel of the vessel,but commercial and military drydocks are available which have flushsides and are more suitable for towing or propulsion through the waterfor significant distances. Some models of floating drydocks have wingwalls which fold downward onto the pontoon hull for easier transport.

Applicant considers the essential components of a floating drydock to bea hull with a bottom which is substantially flat inside and is joined toside “wing” or hull portions extending vertically upward from this flatsurface on their inner sides and preferably joined smoothly to thebottom on their outer sides. The vessel thus formed has a cross sectionlike an open-topped box, with at least one end normally left open andunobstructed to allow the entry of vessels to be drydocked. Optionalaccessories include cranes or other hoisting equipment atop at least oneof the side hull portions for working on drydocked vessels and gates orother enclosures at bow and/or stern to help retain these vessels inplace and prevent the free entrance of water during towing at sea.

The operation of floating drydocks is simple in theory but can bedifficult in execution. When at least one vessel is to be drydocked, thedrydock is anchored, moored or otherwise secured in place as firmly aspossible to limit movement during the docking and undocking procedures.Suitable blocks and supports are carefully placed on the drydock bottomand secured in place so that the vessel to be docked can be emplacedthereon to hold it firmly in place without damage, much like placing anautomobile without wheels on blocks. Using valves and pumps asnecessary, the bottom and sides of the drydock are flooded sufficientlyto sink it to a level where the upper surface of its bottom is farenough below the water's surface to allow the entry of the vessel to bedocked without touching any of the blocks.

The docking officer carefully supervises the movement of the vessel intothe flooded drydock and its positioning directly above the blocks andsupports upon which the vessel's bottom is to rest. Then, maintainingthe relative position of the vessel to the drydock as exactly aspossible with the aid of mooring lines or other suitable means, theflooded portions of the drydock are pumped free of water or “blown” soas to raise the drydock to bring the blocks and supports into contactwith the docking vessel's hull. After a diver carefully checksunderwater that all blocks and supports are in proper position, morewater is pumped from the drydock's tanks to raise the upper surface ofthe bottom well above the water surface. The vessel can then be workedon from top to bottom and stem to stern. When repairs, painting or otherservices are complete, the process is essentially reversed to undock thevessel. Floating drydocks can be very helpful in providing drydockservices to relatively small vessels such as submarines, patrol craft orfishing vessels in advanced overseas operating areas or temporary bases.

An article in Towline (Moran Towing Company, ca. 2001, of record)relating an operation of towing a floating drydock from China to Maineillustrates the potential difficulty of towing such a vessel, with highfreeboard and considerable sail area, over long distances withunpredictable weather, and thus highlights the advantages of the presentinvention for enabling worldwide operations with floating drydocks aswell as the “bundled” groups of prefabricated construction componentswhich can be transported as components of a modular ship. Byincorporating a floating dry dock as the midship section of a vessel ofthe present invention, it can be transported faster and with bettercontrol. In addition to providing a transportable floating drydock forconventional docking applications, such drydocks can also be employed asplatforms for mobile plants for the production of precast concretemodules, as described below.

FIG. 65 shows a floating drydock 820 incorporated into the modular shipof FIGS. 43 and 44 as the midship section 570, the drydock 820 beingsecured between the bow and stern sections (558 and 552, respectively)of the vessel with suitable modular mechanical fasteners 832 asdescribed for the securing of assemblies of floating rectangular boxesin the discussion above of FIGS. 43 and 44. Cables 568 can optionally beused to supplement these connectors as shown in FIGS. 43 and 44 andherein. Suitable mechanical fasteners for hull inserts in modularvessels are also disclosed in U.S. Pat. No. 2,369,615, which isincorporated herein by reference. The floating drydock 820 of FIG. 64 isshown in FIG. 65 as incorporated into a modular ship comprising bowsection 558 and stern 552. The drydock comprises representativeaccessories including a crane 830 and gates 828, but such items could beremoved and stowed for towing, or shipped separately to make thecomplete vessel more seaworthy. Similarly, drydocks without projectingsponsons or pontoon parts 824 would provide a more streamlined vesselfor navigating over substantial distances. With larger, sectionaldrydocks, at least one separate section of the dock could be carried asmidsection 570. Since floating drydocks sometimes need to be transportedlong distances to areas were they may be needed urgently, it should beapparent that integrating such unwieldy vessels into a modular shipwould provide for faster, smoother and safer transport overseas. Anexample of the perils of direct towing of a floating drydock is found inthe Towline article cited above.

During the period from after Hurricane Katrina (August, 2005) untilapproximately June of 2006, there has been a project underway totemporarily enhance and strengthen the levees along the MississippiRiver. In that there is little capacity for volume production ofconcrete products in the heavily damaged Gulf region and a minimum costsystem is desirable, it is proposed to utilize readily available andperhaps partially damaged shipping containers. Such containers oftenaccumulate in port areas such as New Orleans because it is more costeffective for shipping companies to produce and utilize new containersat overseas origins than to return and reuse the containers which havereached U.S. ports. Their empty weight is about 4,600 pounds for 20 footcontainers and 9,400 pounds for 40 foot containers. They are readilytransportable by truck, train, barge, and ships of the intermodaltransportation system. Secondly, helicopters can lift and transport theempty containers to the levees.

The containers can be used to raise the tops of the levees to preventovertopping by higher category hurricanes. While they are mostlywatertight, they may need an impervious liner or sealant to hold waterwhen used above sea level. For longer service one might want thecontainers treated with an approved coating such as Coal-Cat or apolyurea. They would be placed atop or dug partially into the levee,along with water-impervious plastic or sheet pile as necessary to reduceundermining (or any other revetment, weakened dam, etc.) to bereinforced or repaired. Screw anchors could be used to secure them inplace and suitable mechanical attachment means used to connect themtogether. Then they could be pumped full of water and/or sand to presenta large mass to impinging waves or storm surges. They could be backed byearth and/or rock revetments on the seaward and/or landward sides toassist in maintaining the boxes' position. Pipes with valves or plugscan be installed on the top and bottom sides of containers to facilitateflooding and draining the boxes, as disclosed elsewhere herein.

Secondly, in addition to the temporary or permanent use of recycledshipping containers, prefabricated rectangular and/or hexagonalcontainers made of precast concrete, plastics or metal as disclosedherein can be installed at the toes of levees, dams, or revetments toprevent scour on the waterside and leak-through or blow-out protectionon the landward side. Here they could be filled with sand and/or waterand connected together to form a very large integrated mass. Impervioussheet material on the riverside and semi-permeable geotechnical materialon the landward side (as illustrated and discussed in regard to FIGS.115 and 116) can control water entry into the dam or levee and controlwashout on the landward side, respectively.

Thirdly, such prefabricated containers can be used to help prevent orplug breaches in levees, barrier islands or dams. In emergencies,shipping box containers can be transported and airlifted into place,connected together, and floated into place. Then they can be sunk intoplace by opening valves, plugs, or in emergencies using mechanical orexplosive means to break the watertight integrity, as disclosed hereinfor precast concrete modules. Cables on the ends of a linear array ofconnected boxes can be tended to guide the “plug” into place and thensecure it in place. To strengthen the tops of weak spots in dams andlevees, such arrays of boxes can be used as buffers near weak spots asfloating, semi submerged, or submerged containers.

Examples of such operations are illustrated in FIG. 69, where levee 900has been breached and quantities of metal shipping containers 82 arebeing maneuvered into place to repair the breach. Water is surging fromriver 902 through the breach 901 as shown by arrow 1051 and floodingland areas 905 on the other side. On the leftmost portion of the levee900, a truck 1063 has delivered a single container 82 using trailer1064. The container could be unloaded and positioned atop levee 900 orin the breach area by using a crane (mobile, floating or installed onthe truck, not shown here) or easily lifted off and emplaced by a heavylift helicopter 1065, which is shown carrying a container 82 fromanother source. Barge 600 has been employed to deliver six containers82, temporarily anchored in place by at least one cable 106 and anchor615. Tugboat 310 is towing an array 904 of three containers 82 via cable106, using another cable 106 and attached anchor 1066 astern of thearray to assist in maneuvering array 904 into position across breach 901where they can be sunk into position to assist in closing the breach.The current created by water escaping from 902 through breach 901 canassist in maneuvering such an array into position, given a skillful tugoperator and other aids to positioning. Once large arrays 904 are inplace, additional containers of various sizes and shapes, sandbags andthe like can be placed as necessary to effect at least a temporaryrepair and reinforcement.

FIGS. 115 and 116 illustrate other arrangements of rectangular boxes 100to reinforce an existing levee 900 standing between a river with surface902 and bottom 903 and the ground surface 905 on the other side. Alinear array 911 or row of boxes 100 of various suitable sizes can beemplaced atop levee 900 to prevent surges of water from overflowing,preferably with the boxes securely interconnected by mechanical means(not shown here) and anchored to the levee surface by suitablemechanical fasteners 913 extending into the upper surface of levee 900.Single boxes 100 or arrays 911 thereof can be emplaced at the inshoreside of the levee as shown at 914 to prevent and/or plug leaks and/orprevent erosion of this side of the levee when and where required.Preferably sheets of filtering material 915 such as woven or nonwovenfabrics are installed between box 914 and the earth of levee 900 andground surface 905. Similarly, single boxes 100 or groups arrayedlinearly and/or stacked as shown at 916 can be installed underwater atthe riverside base of the levee in areas vulnerable to erosion toprotect it from erosion and hydrostatic pressure. Sheets of waterresistant or waterproof materials 918 are installed between the boxes100 in stack 916 and the levee to prevent leaks. Additional boxes 920 orarrays thereof can be floated on the surface into position to be sunk,where they are filled with water and installed in the riverside tostrengthen a weak spot or to plug a breach in the levee.

A specialized system of containment using rectangular modules can beused to rebuild barrier islands on the Gulf Coast to mitigate hurricanewave damage. These shipping container-sized (i.e., about eight feetsquare by forty feet long) modules are sized to be easily transportablewithin the intermodal transportation system on trucks, trains, ships andbarges, as disclosed above and in previous patents. The components ofthis system are disclosed in U.S. Pat. No. 6,491,473. They can be usedto build structures including underwater “reef” breakwaters,semi-submerged breakwaters, and concrete “backbones” within sand duneson the back beach of an existing barrier island or similar formation, asdescribed above with regard to FIGS. 41 and 42.

Where a barrier island 950 lying between, e.g., a sound or bay 952 andan ocean or gulf 954, is eroded below sea level or is just awash(imminent as shown in FIG. 71, depending upon tide levels), anopportunity exists to further engineer, test and later build a fullscale system to rebuild the island. An array 956 of rectangular modules100 is laid out and connected together in square or rectangularsubarrays 958, as shown in FIGS. 70 and 71, top and side views,respectively. Although they may be closed during transport to the siteto be repaired, generally the modules will be installed with open topsto facilitate their filling with sand, during installation and/or bysucceeding storms.

The rectangular modules 100 used can be transported to the barrierislands aboard container ships, barges or similar vessels, or by tugstowing arrays of floating watertight modules. On calm days, they can bebrought ashore in barges or suitable landing craft or simply floatedashore by themselves. On the beach, heavy equipment such as crawlercranes or large excavators can move the boxes to their final sites forassembly of the arrays described herein. Alternatively, specializedtracked “high lift” container movers such as used in port facilities canbe used. Once arranged in the desired arrays and patterns, the modulesare securely fastened together and to the beach using suitablemechanical fasteners disclosed herein. Initially the boxes can be atleast partially filled with water to provide additional mass. The boxescan be filled with sand as the grid is filled when the beach isnourished with sand pumped from nearby sand deposits. Alternatively,natural processes during storms will tend to fill the open modules andthe grid cells as the waves containing suspended sand are slowed by thestructure.

The individual rectangular subarrays 958 can be on the order of 200 feetsquare, or similar sizes as required by the particular location andinstallation, and can be repeated as required to “cover the ground”.Dotted lines 964 in FIG. 70 indicate potential expansions of the arraysto form a grid pattern to rebuild the beach areas as required ordesired. As storm tides overtop these containment modules with opentops, sand will accrete. Further, the containment area(s) can berenourished by pumping sand from offshore borrow areas. In addition,once rebuilt, further accretion and erosion prevention can be achievedby using such modules to form submerged “reef” breakwaters (960 in FIG.71), semi-submerged breakwaters or sills (962 in FIG. 71), and abackbone of a new sand dune, as shown in FIGS. 41 and 42 of U.S. Pat.No. 6,491,473. Thus one can repair and “regrow” a much larger “barrierisland breakwater” incrementally by judicious placement of arrays ofprefabricated rectangular modules to help control the accretion anderosion of sand.

Alternative techniques may be required where the barrier islands and/orbottoms of the bay and/or sea contain more silt than sand. In suchareas, e.g. the Mississippi delta of Louisiana, it has been found thatmany structures emplaced to build up or repair barrier islands simplysink deep into silt and mud. One solution to this problem is to employrectangular boxes similar to those described above, but with closed topsand carefully placed holes for flooding, draining and venting the boxesunder various tidal conditions. Such boxes can be emplaced with opentops, ballasted, and then “tuned” to a weight which will keep the boxesin place during most conditions, but delay their sinking into mud orsilt.

FIG. 72 shows a closed or open top box 100 placed atop a barrier island950 adjacent ocean 954, with some sand 933 having accreted on the bayside of the box. Sufficient sand 933 and water 602 have been pumped intothe box during installation to provide the desired mass to controlbuoyancy. At least one large drain hole 87A, and preferably a pluralityof same, are provided near the top of the box on the seaward side, at aheight where storm surges or high surf (as shown in FIG. 73 will allowmore water to enter and ballast the box to keep it in place. Under suchconditions water may pass over box 100 (or arrays thereof) to bring thewater level of bay 952 up to the level of the boxes. Optionally, aplurality of vents 84 can be placed in the tops of boxes 100 to allowair to vent easily as water enters large flood holes 87A, and then toallow waves passing over the boxes to completely fill them through thevents. Smaller drain holes 87B are provided near the normal expectedmean low water level of ocean 964, to allow the water entering duringstorms to gradually drain as the high waters recede, returning the boxto an appropriate ballast state for conditions as they develop. Thereduced mass of the boxes resulting from drainage after the storm passeswill again mitigate subsidence.

Concrete or metal boxes of rectangular or hexagonal cross sections couldbe used as vertical cores for levees, dams or similar structures. Theirwidth, height and length would be commensurate with the site-specificconditions needed for the structure. The rectangular sizes mostconvenient for intermodal transportation would be boxes with outsidedimensions about 8.5 feet high, 8 feet wide, and 10, 20, or 40 feetlong. Containers or modules 12 feet wide and having fractional crosssectional dimensions totaling about 8.5×8 feet are also possible, asdisclosed in U.S. Pat. No. 5,697,052 cited above. Boxes shipped withinmodular steel frames can be smaller than the standard intermodal size.The boxes can be compartmented for strength as needed. Further, they canbe equipped with suitable pipes and valves to allow them to be filledwith a liquid such as water or a slurry of sand, cement or otherflowable fills as desired for strength and mass.

Where a variable mass is desired a pumpable liquid is used. In thislater case, the boxes are installed vertically and jetted down in soil,which may be unstable. They are then filled with a liquid, most likelywater or seawater. This extra weight will assist in “pumping” the unitdown in sand or alluvial soils. Pipes can be built into the boxes topass gas and liquids (normally air and water) to assist jetting materialfrom under the box, using the air acting as a “lift pump” to lift thedisplaced material upward. When in place the boxes are linked togetherby suitable mechanical fasteners such as disclosed above. Should thecore of the levee tend to subside, the water used can be pumped or blownout of some of the compartments in order to achieve “neutral buoyancy”and to “tune” the mass of the core commensurate with the base soilconditions.

Where the soil conditions dictate, a pair of horizontal “collar” boxeson each side of the vertical levee boxes can be clamped by cables toeach other. This provides a greater base area at some point, probably onthe lower portion of the vertical levee boxes, to impede subsidence insoft soils.

The hexagonal and/or rectangular modules of the invention can be used toform, reinforce or repair a levee or dam. They can be dug into hardground or pumped down with air and water jets in certain soils that maybe unstable, as described above for “jetting in” the L-walls ofApplicant's prior inventions. Hollow modules can be installed empty andthen filled with water, or a slurry of sand or cement. They can befilled with a liquid such as water or water-sand slurries for weight andthen “pumped” down using external jetted water and air mixed or wateralone. When the module has reached the proper depth, pumping is ceased.Then to prevent further subsidence, some of the water can be pumped outof the module until the weight is equal to the “buoyant force” of theunstable soil in which they were placed. In other words, the effectiveweight or displacement of the modules can be varied over their life inorder to maintain a “neutral buoyancy” by pumping or blowing water in orout of a module located in unconsolidated soils. This procedure isanalogous to pumping or blowing the tanks of a submarine to modify itsdisplacement in water and maintain neutral buoyancy at a particulardepth.

FIG. 117 illustrates in cross section the use of an array 904 ofrectangular modules 100 to build or reinforce a levee 900 forming anembankment or berm to prevent the waters of river 902 from overflowingthe banks. The river bottom 903 slopes up gradually to levee 900. Theground level 905 on the opposite side of the levee may be higher orlower than river bottom 903 or river surface 902. Rectangular boxes 100can be arranged vertically and/or horizontally in an array 904 to createa vertical wall inside levee 900 to strengthen it, even in the face ofthe hydrostatic pressure of high water and/or erosive forces of rapidcurrents. Such reinforcements are most effective if built into the bermforming levee 900 early on, so that the modules can be firmly implantedwithout the need for extensive excavation. The bottoms 100A of boxes 100can be open or closed; open bottoms may facilitate the firm emplacementof the boxes in soil, especially when installed during construction ofthe levee 900. Additional modules 100 can be added to the top of array904 as it becomes necessary to raise the levee. Optionally, areinforcing “collar” or support 906 of rectangular modules can beinstalled on at least one side of this wall to help reduce subsidence.

FIG. 118 is a top view of a portion of array 904 and collar 906, showingthe ends of upright modules 100 forming the wall and the tops ofhorizontal modules 100 forming a double-sided collar 906. Verticalpipes, braces or tubes 908 are provided in at least a portion of theupright modules 100 to aid in their installation. As shown in these andFIG. 119, the modules are all securely interconnected by suitablemechanical connection means 910, as disclosed above and shown in FIG.117. FIG. 122 shows a side view of the wall 904 alone, with collar 906removed for clarity. At least a portion of vertical modules 100, shownin partial cross section on the right, are divided up into a number ofinterior compartments (here, A through E) and fitted with pipes ortubular openings 912 which are fitted with plugs and/or quick-connectfittings for the ready passage of air and/or water in the installationor variable ballasting of array 904. Such an array can be assembled insections and floated into place if the levee area is underwater at thetime of installation, or alternatively can be assembled module by moduleif dry working areas are available.

FIGS. 113 and 114 illustrate the use of arrays comprising hexagonalmodules of the invention to build or reinforce levees, in mannerssimilar to those described above for rectangular modules. As in FIGS.117-119, an array 904A of hexagonal modules 751 is incorporated into thecenter of levee 900 to strengthen it. The modules 751 in linear array904A are secured together by suitable mechanical fasteners (disclosedherein, not shown here). Similar to the description of the rectangularboxes herein as levee supports, the arrays 904A of hexagonal modules 751can have installed a “collar” 906 of rectangular boxes 100 extendingover at least a portion of the length of the array and on at least oneside, to enhance their stability and prevent subsidence in poor soils.“Armor stone” 756 or concrete reinforcing mats 746 such as disclosed inU.S. Pat. No. 5,697,736 can be installed along the levee's river side ofthe arrays 904 or 904A on the slope of levee 900 to protect the leveeand array against erosion. The mass of individual modules 751 can bevaried by the amount of water admitted into the multiple internal tankssuch as A, B, C, D and E shown in FIG. 113 and discussed above withregard to rectangular modules.

FIGS. 110, 111 and 112 illustrate further applications of hexagonalmodules in the repair or reinforcement of levees. FIG. 110 shows module751 being floated into position alongside levee 900. Once lodged againstthe levee, module 751 can be partially flooded to create a weightdifferential when tilted, maneuvered into a suitable vertical positionby any suitable means such as a floating crane (not shown here) and sunkinto place closely adjacent to levee 900. By excavating into the bottom903 adjacent levee 900 and “jetting in” module 751, it can be settledinto a stable upright position with its base forming part of the leveebase. Using passages 811 of FIG. 86 to jet a mixture of air and waterfrom the six corners, the module can be “steered” by differentiallyjetting from one or more conduits at a time. If a series or array ofsuch modules are positioned in this way, the space between the modulesand the riverside slope of the levee can be filled in with sand, rock,aggregate or other suitable fill to expand and strengthen the levee.FIG. 112 illustrates the use of hexagonal modules 751 to build up apartial levee 900 or repair an eroded levee to create a symmetrical,broad levee with the planned contour 900B. In this case module(s) 751are moved into position from the inshore side of levee 900, thenimplanted firmly into shoreline surface 905. The space between surface900A and eroded or partial levee 900 can then be filled with appropriatematerials and the inshore side of the module(s) used as support to buildup the inshore side as well to form a broad, symmetrical levee 900 ofgreater strength.

Using vertically oriented hexagonal or rectangular modules, a flood gatecan be manufactured from, for example, a hexagonal module or arraythereof constructed in two portions. As shown in FIGS. 74 and 75, thelower portion is fixed to the river bottom 903 and to its adjacentmodule. The top portion is constrained by rails or other suitable guidesto allow it to move up and down in the water surrounding it on both theriver or reservoir sides and the upstream or downstream sides. FIG. 74shows a three-module linear array 1020 having two hexagonal modules 751flanking a floodgate assembly 1021 as shown in the side views of FIGS.75 and 76. Assembly 1020 is immersed in water such as a river 902,extending into river bottom 903. Assembly 1020 would normally be aportion of a levee extending to the right and left from the assembly asshown, and a levee, dam or other water retention device couldincorporate several such floodgate assemblies. The upper portion 1021 ofa central split module or vertical array thereof which serves as theupper portion of the gate is visible in all three views. FIGS. 75 and 76show lower portion 1022 of this central gate module.

FIG. 77 provides a detailed top view of an embodiment of gate assembly1020 in which gate or upper module portion 1021 is slidably mounted onhexagonal modules 751 by conventional tongue and groove slides 1018.Stiffening beams 1017 or other suitable mechanical reinforcements can beadded to maintain the relative positions and rigidity of the threemodules of the assembly to prevent binding of the gate during operation.Optionally, screens, shields or the like could be hung from stiffeningbeams 1017 on the river side of the gate to prevent debris from enteringthe gate.

FIG. 75 shows the floodgate in closed position, with the upper portionof the gate 1021 resting flush against the lower portion 1022. When itis desired to divert water from one side to the other, such as from ariver within levees or to release more water from a reservoir, themovable top portion 1021 is made buoyant by pumping or blowing its waterballast from its chambers using, e.g. air compressor and pumping means1024, high pressure air tank 1023 and pipe and flexible hose 1025.Ballast water can exit from outlet 1027 to either the river 902 orreservoir 1048 (shown in FIG. 78). A flood and drain opening 1029 isprovided in the side of upper portion 1021, and is normally kept openunless closed for maintenance. As upper portion 1021 becomes positivelybuoyant it floats upward as shown by dotted lines in FIG. 75[I.2] andsolid lines in FIG. 76[I.3], opening a gap 1028 between the two portionsof the flood gate 1020 and allowing water to flow from the river orreservoir to the other side of the gate. As an alternative to usingcompressed air for deballasting as described above, pumping means (notshown here) could be installed to move water in or out of upper portion1021 of gate 1020.

When it is desired to close this flood gate 1020, water is simplyflooded or pumped into the movable top portion 1021 to make itnegatively buoyant again, thereby causing it to descend and close theflood gate.

FIG. 78 illustrates a practical installation of a floodgate assembly1020 in a levee or dam 1050 comprising hexagonal modules 751 along, e.g.river 902. Behind the levee or dam 1050 is a small basin or reservoir1048 enclosed by an array 1052 of hexagonal modules 751 (which caneasily be arranged to form arc-shaped arrays) with a weir (which can bea V-shaped groove) or pipe 1053 to provide flotation on both sides ofthe floodgate. The weir 1053 would accommodate a small amount of waterflow 1051 from leakage when the reservoir is full. Gate 1020 is openedas needed by raising upper module portion 1021, allowing water (withsilt included) to flow into reservoir 1048. Passages 1053 can be allowedbetween adjacent modules 751 in array 1052 at different levels, withthose at lower levels allowing both water and silt to gradually flow outinto adjacent wetlands and optional upper pipes or suitable connectionsavailable to direct clear water to a potable water plant or irrigationditches. If arranged and managed properly, a larger reservoir 1048 couldbe used for a community water system.

FIG. 45 is a side view showing the vessel (550) with bow section (558)and stern section (552) again connected together, box module (562)having been removed by reversing the sequence of steps described above.Thrusters or mini-tugs (not shown here) can be carried on the forwarddeck and/or in a forward hold and offloaded using crane (560) tofacilitate this process. In FIG. 45, a portion of the module tensioningsystem has been loosened and crane (560) is lifting the first box (101)to be offloaded. Depending upon the depth of water near shore and thepositions where the boxes are to be installed, the vessel and crane maybe able to deposit the boxes in the water directly above or near theinstallation point, or near the installation point ashore.Alternatively, the boxes can be placed into the water near shore andmaneuvered into installation position by mini-tugs or other suitablecraft. Where appropriate, crane (560) and/or a similar crane installedon the stern section of vessel (550) can be used to remove individualboxes (101) which have been disconnected from box module (570) before ithas been disconnected from the bow and stern sections of vessel (550).

FIGS. 46 to 48 illustrate another method of transporting and installingarrays of precast boxes of the invention. FIG. 46 is a side view of abarge (600) or similar vessel floating in water (602) over bottom (610)where a breakwater is to be installed. Vessel (600) can beself-propelled, in which case propeller (620) and associated propulsionsystems are provided. Precast concrete boxes (604) are connected bystainless steel cables (606) (or other suitable mechanical means) andarranged on deck (612) in position to be unloaded as an array via ramp(608). The boxes can be the special perforated and slotted “breakwaterboxes” disclosed in U.S. Pat. No. 5,697,736 and illustrated herein inFIG. 4 (having thin concrete knockouts or plugs), but can also be openboxes as in FIGS. 10 to 12 or closed boxes fixed with flood/drain andblow/vent valves as illustrated in FIGS. 16/17. Ramp (608) can be heldin position during operations by using suitable mechanical restraintssuch as cables or hydraulic rams, as well as floats.

The array of boxes can be unloaded from the barge by dropping a heavyanchor (614) which is attached to the array by extended cable (607),then backing the barge (by self-propulsion or tug, not shown here) toexert tension on cable (607), as illustrated in FIG. 47. Barge (600)will require a smooth, level deck upon which the array of boxes can bearranged, and providing rollers or lubrication before the boxes areloaded and connected would be helpful. FIG. 47 illustrates the array ofboxes (604) floating on the surface (602) and interconnected by cable(606) (not seen here), with the boxes pulled closely together. One endof cable (607) is still held by anchor (614), but the array of boxes hasbeen moved closer to that anchor by winches or boats to bring it nearthe point where the breakwater is to be installed. At the other end ofthe array, cable (606) passes through block (618) on anchor (615), whichwas dropped from the barge deck after the last box slid down ramp (608).Clamps or other mechanical restraints (616) and (617) position the arrayof boxes at preplanned portions of cables (606) and (607) after thedesired amount of tension on cable (606) and the desired position of thearray is attained. This is accomplished by applying force to the bargeend of cable (606) via a winch (not shown) or other appropriate device.

When the array is in optimum position for installation as determined bynavigational or global positioning system fixes, all boxes are sunksequentially or simultaneously by remote control or manual means, andallowed to settle into their installed positions to form a submergedbreakwater or reef (622) as shown in FIG. 48. Cable (606) can then besimply cut from the barge deck, or if desired, a diver can be employedto secure cable (606) to block (618) on anchor (615) and the excess cut,to provide extra security for the breakwater. As discussed in the patentcited, at columns 8/9, such breakwaters can be very beneficial inreducing or eliminating the presence of swells in harbors which are atleast partially exposed to open water. As an alternative, theinterconnected boxes can be left floating to mitigate passing waveenergy.

FIGS. 49 and 50 illustrate how the precast, intermodal concrete boxescan be used to construct buildings for use either above or below groundor water. Dwelling structure (650) includes first floor (654) and secondfloor (652), all constructed of precast concrete boxes of variousstandard sizes and proportions, being interconnected and stacked to formthe two (or more) stories.

The concrete boxes are amenable to intermodal transportation as well aslifting and placement on the ground (or actually in water, if the bottomunits are waterproof) or stacking, as illustrated in FIG. 49. Doors,windows, open walls, conduits for utilities, and the like (not shownhere) can easily be included for use in these standardized boxes and/orcut during installation/assembly. The walls of the precast boxes ineffect become interior and exterior walls, floors and ceilings of thevarious rooms or spaces contained within the structure.

Because the concrete is strong, resistant to liquids and vermin, it canbe used in wet areas, acidic soils, underground, on water, under waterand in other challenging environments. It is ideal for constructingstrong, relocatable structures, such as for military or security areas.Such precast boxes can be ideal for constructing bunkers, falloutshelters, underground or underwater storage facilities orearth-sheltered homes. FIGS. 49 and 50 illustrate the employment ofprecast concrete boxes of various sizes and proportions suitable forforming various typical rooms of a combined dwelling/office structure.For example, large unfinished modules (658) can be used for garages orthe like, and smaller modules (655) and (656) can be used for bathroomsand bedrooms.

FIG. 54 illustrates a shoreline reinforcement system installed along ashoreline having a sloping beach, a low bluff and sand dune systemsshoreward of the bluff. A series of L-members of the present invention(or large T-walls) (2) are installed along the base of the low bluff toform a seawall (740), with footers (6) being covered by rubble and fillgraded down from the dune systems. Splash plates (10) of the L-membersprotect against scouring by wave action. Preferably, small rocks underarmor stone are used to cover the splash plates to further resist scour(not shown in this figure; see FIG. 4 of U.S. Pat. No. 5,697,736).Several groins (742) perpendicular to the seawall are formed by invertedT walls (50), extending down the beach and along the shoreline toprotect the areas most vulnerable to erosion. Preferably the invertedT-walls are secured to the seawall, as shown in detail in FIG. 11 ofU.S. Pat. No. 5,697,736, by having base sections (53) of the invertedT-walls inserted under splash plate (10) of the wall, with the stem (52)of the T passing through cut (60) in the splash plate. Additionally, atleast one series (744) of inverted T-walls (50) is installed parallel tothe seawall, further down the beach. This provides a strongerreinforcing structure and has the added beneficial effect of helping toform a “perched beach” or area where sand, pebbles and other desiredmaterial can accrete. Concrete reinforcing mats (746) such asCable-Concrete or the interconnected concrete tie mats of U.S. Pat. No.5,697,736 are installed behind the seawall and the row(s) of invertedT-walls parallel thereto to protect the beach from erosion and allow forfurther accretion of sand, etc.; and below the lowest line of invertedT-walls to protect against Scour Mats (746) comprise rectangularsections of concrete (748) connected together side-by-side by cables(750) or other suitable connecting means. All the concrete componentsare interconnected by suitable connecting means or fastening means attheir points of contact.

The system shown in FIGS. 55 and 56 and described in Example 3 of U.S.Pat. No. 5,697,736 was designed, built and installed for reinforcementof the Potomac River bank on residential property at Colonial Beach, Va.Starting at the right (northern, upriver portion) of FIG. 55, a portionof the bank was designed as beveled and protected by armor stone (756)against erosion by the current. The angle of the beveled portion wasselected to help to deflect floating debris, ice and the like.Approximately 200 feet of the bank was reinforced by sections of L-walls(2) installed to form a sea wall. After entrenching the beach below thebank and positioning the L-walls with their keys (8) firmly placed andleveled, the upper bank was graded and used to fill over granular fill(744) (rocks, gravel and sand) that have been used to cover footers (6)of the L-walls. Weep holes (14) are provided in the L-walls fordrainage, and the walls were joined end-to-end by bolts or othersuitable connecting means. The splash plates (10) of the L-walls werecovered first with core stone (746) over a layer of geotextile (29),then with armor stone (756) to protect against storm and ice damage. Thesouthern/downstream (left) end of the wall was protected by armor stone(756).

A series of five groins (742) was installed, extending approximately 20feet from the wall and approximately perpendicular thereto. The groinswere formed of inverted T-walls approximately 3 feet high by 3 feetwide, and placed so as to nourish the present beach with sediment. Apier groin (758) also extends from the wall in a perpendiculardirection, for about 30 feet. The pier groin was constructed of inverted“Double-T” units. This system was designed to protect the presentlyeroding river bank, encourage accretion on the present beach and enhancerecreational use of the area.

Modular Ships Comprising Hexagonal Boxes.

FIGS. 57, 58 and 59A through 59F illustrate a vessel similar in form andfunction to that of FIGS. 45 to 48, but constructed of individual hollowmodules of hexagonal cross section, assembled in vertical positions toform honeycomb arrays which offer a high strength-to-weight ratio andthe convenience of removing and installing modules for a variety offunctions in the same spaces. These hexagonal modules can be formed of avariety of materials including metal, wood, plastics, polymericcomposites and precast concrete, the latter material being preferred inthe present context. As with the modular concrete boxes disclosed above,the hexagonal concrete modules can be cast and outfitted with variousopenings, compartmentation apertures, fixtures and mechanicalconnectors. Methods for precasting reinforced concrete structures arealso disclosed in U.S. Pat. No. 5,697,736. When used to form shipcomponents or other floating structures, the hexagonal modules arepreferably watertight.

In addition to serving as ships or barges, self-propelled or otherwise,large arrays of hexagonal and half-hexagonal modules assembled invertical orientation can be transported from an assembly point tooffshore areas for assembly in larger arrays to form floating bases ofvarious types. FIG. 98 illustrates the assembly process with three largearrays having overall contours similar to those of the vessels of FIGS.57 and 58. Each array comprises hexagonal modules 751 and half-hexagonalmodules 753. The top two arrays 804 have similar bow contours to thoseof the vessels of FIGS. 57 and 58, although various shapes can be usedaccording to mission requirements. Both of these arrays have stern orafter niches 804A (much like the lines of separation for the stern ofthe vessel of FIGS. 57 and 58).

As indicated by the arrows between the two upper arrays, they can bemoved adjacent to each other in reasonably calm waters, using tugs,pusher boats or other suitable small craft discussed elsewhere herein.Once the arrays are brought into close contact along their full lengths,they can be moored together in conventional fashion, using mooringlines, chocks and bitts in classic fashion as any pair of vessels aremoored side by side. Mooring lines can also be used to bring the arraysinto close contact, using winches or other tensioning means (not shown),to avoid damage which might be caused by excessive momentum developed byone array or the other when pushed by a tug or the like. Conventionalfenders or other cushioning materials can be used between the arrays toavoid damage as they are brought together. Depending upon the mission,such arrays could be kept moored together or fastened together in apermanent or temporary fashion using various suitable mechanicalfasteners, cables and the like, as discussed elsewhere herein.

Array 806, shown below the two arrays just discussed, has a bow 806Amodified to fit into stern niche 804A of those arrays, and so can bepushed into position in the stern of such an array, moored andoptionally secured permanently or temporarily thereto to form a largerarray. Since array 806 has the same type of stern niche 804A as theother arrays described, any number of such arrays can be broughttogether and joined bow to stern. Such floating platforms, if properlyequipped, could be used as mobile disaster relief platforms from whichhelicopters, airboats or the like could operate.

Vessels or other floating arrays comprising hexagonal modules can beemployed for various military and civilian missions. For example, FIG.99 is a top view of a floating platform or sub pen 1000 made up ofhexagonal modules 751 and half-hexagonal modules 753 which can be afree-floating platform similar to that depicted in FIGS. 57 and 58,anchored or moored, or integrated into a floating port (“SEABASE”) arrayas discussed herein. This platform can serve as a mobile base forsubmarine maintenance, resupply and crew change. The platform can beself propelled as described for the vessel of FIGS. 57 and 58.

A civilian application for arrays 804, 806, 1000 or the like could bemobile, floating “SEAHOUSES” or seagoing apartments. Interior units,“waterfront” units and hexagonal units on “moon pool” sides whereprivate boats could be kept, would appeal to residents of various incomelevels. Units of various sizes such as single, one and one half or twohexagonal modules or arrays could be provided. Porches and windows wouldbe available on the upper decks of multideck platforms as well as onopen air roof spaces.

The platform normally has at least one defined bow end 760 andoptionally can have a removable stern section 1006 which separates fromthe main body along lines of separation 1004 and can be moved aside forsubmarine entry or hinged at the outer edges with hinges 1011 to openlike double doors along another line of separation 1004. Alternatively,stern section 1006 can be ballasted or deballasted to sink and risealong rails or other suitable guides 1018, as shown in FIGS. 101 and 77,and discussed below. An interior cavity 1001 is provided by thestructure of the platform, the cavity having length and width sufficientto accommodate the mooring of at least one model of operationalsubmarine 1005 (as shown) or small surface vessel therein. The cavitycan be completely open above the platform (as shown in cutaway portion1008) to permit the submarine to enter directly while the removableportion 1006 is open, but preferably a top layer of modules 1002provides a “moon pool” 1003, open to the water to allow access frombelow and closed above, which is dimensioned to allow a submarine tofloat into position from below, much as modern submarines explores polarregions, finding areas of shallow ice (by sensors including periscopes,underwater television and under ice sonars) where the vessel cangradually surface in a vertical direction to force its way through theice.

The platform 1000 is configured to provide a “moon pool” 1003 and acavity 1001 above with sufficient clearance to allow a submarine tosurface and float on the water surface therein (at various vesseldrafts) without impacting the modules overhead with the uppermostprojections of the submarine. The level of water in the moon pool 1003relative to the inner surfaces of modules 751 and platform bottom 1007can be controlled by varying the pressure of the air in a closed cavity1001. A portion 1009 of an upper module layer or deck 1002 is shown cutaway in FIG. 100 to reveal the submarine 1005. Depending upon the scaleof the platform and expected operational requirements, ample clearancescan be provided for a variety of submarine models, or particular models.Conventional catwalks and mooring facilities concealed within the upperlayers or decks 1002 of modules 751 of platform 1000. The latterconfiguration of course provides secrecy as to the submarine's presenceand operations, provided the surrounding water is deep and/or darkenough to preclude visibility from above. The closed top configurationalso provides for better control of the depth of the moon pool 1003.

FIG. 101 is a stern view of platform 1000 with a closed top to provide a“moon pool” inside, a submarine 1005 berthed therein and stern section1006 ballasted down to provide sufficient clearance for the submarine toenter directly on the surface. The mechanisms for lowering and elevatingstern section 1006 would include rails or other guides 1018 (See FIG.77.) along lines of separation 1004 paralleling the outer walls ofadjacent modules 751 and conventional means for pumping water and air,as discussed herein in FIGS. 74-78 for a levee floodgate which can beraised and lowered in the same manner.

An alternate version of platform 1000 can employ a squared-off bowrather than the rounded configuration 760 shown here. Such a vesselcould be incorporated as the midsection of the modular ship describedabove with regard to FIGS. 43 and 44, in the same manner as the floatingdrydock of FIG. 65, and transported to remote areas of use without theneed for self-propulsion or the greater risks of towing.

FIG. 57 illustrates the assembly of hexagonal modules adapted forvarious functions, all assembled in vertical orientations so that theycombine to form a horizontally-oriented honeycomb array which formsvarious portions of ship (800). Plain open hexagonal modules (751)provide the basic structure of the ship, and can be left empty forbuoyancy or equipped to be filled with water for ballast. Preferably, amajority of these modules are precast with substantially open andunobstructed internal cross sections for maximum versatility in use. Forexample, modules (770) can be filled with potable water or other waterto be stored for use. Half-hexagonal modules (753) (having the crosssection of a hexagon cut from edge to edge) can be used to fill in thespaces along the outer surfaces of the honeycomb arrays to provide aflush surface. Bow section (755) of ship (800) (which can be easilyremovable along lines of separation as with the previous vesseldiscussed above) is shown as including bow propulsion unit (760), twohalf-hexagonal modules (753), three open modules (751) and two cranemodules (764). Operations of typical cranes and bow thruster units (762)are described above in reference to FIGS. 43-45. The hexagonal and halfmodules are configured so as to provide a blunt pointed bow section.Stern unit (763) (also optionally detachable) is shown as including twolateral thruster units (762), a bridge module (776), four open modules(751) and two propulsion modules (759), each fitted with propulsionmotors (760A) and propellers (761). The parallel mid-body section (757)can take up variable amounts of space between the bow and stern units,and is shown as including (from forward to aft) a number of fuel modules(768) (which can contain fuel for aircraft and/or boats as well as shippropulsion), water modules (770), and half modules (753) to provide aflush outer surface on the sides of the section. Elevator modules (772)are provided to transport cargo or other items between the main deck andlower levels of the ship. The various modules are secured together withmechanical connectors (150), as described above, and reinforced withtensioning cables (778) (intermodule connections) and (780) (moduleinternal reinforcements) as required.

Missile modules (766), shown in more detail in FIGS. 59D and 59E, arerepresentative of weapons modules which can be interchangeably installedto provide the ship with offensive and/or self defense capabilitiesagainst aircraft, surface-to-surface missiles, surface craft andsubmarines and/or torpedoes. The same types of modules, extending to thebottom of the ship, can be employed for laying mines or launchingantisubmarine torpedoes.

The individual hexagonal modules are designed to be waterproof, evenwhen provided with access hatches, apertures or other fitting. Thus, astructure such as the ship of FIG. 57 need not be sealed on the outersurfaces or in the spaces between the modules. The modules areinterconnected by suitable mechanical fasteners as described herein andabove, and can be individually disconnected and removed in case ofdamage or the design of certain types of modules for use apart from theoriginal array. At least one module can be fitted out as a lifeboat (asin FIG. 96) and removably attached for quick use in emergencies. Themodules can be produced in any desired size, depending upon the intendedapplication (e.g., from about ten to about 100 feet in length and fromabout twenty to about sixty feet across between sides), but may belimited in size to facilitate transport.

The modules can be arranged and interconnected to form honeycomb arraysby various suitable methods, ashore or afloat, much as described abovefor rectangular boxes. They can be prepared and outfitted in a shipyardor other facility, then moved via (and/or water transport to beassembled while floating in the water. Since assembly while floatingcould require diving services, an ideal approach is to assemble arraysor portions thereof in dry dock. Once the desired array has been formedand all modules connected, the drydock can be flooded, its gate removedand the array towed out for immediate use, further outfitting orconnection with other arrays.

FIG. 58 illustrates variations on the modules which can be used toconstruct ship (800), and FIGS. 59A through 59F are side views ofindividual modules providing more detail. The forwardmost bow module(782) provides water jet propulsion for maneuvering, using trainablethruster nozzles (784). Missile modules (766) can provide for eithervertical or horizontal launching tubes (766A) for various types ofsurface to air and surface to surface missiles. Electric power modules(786) provide power for the ship, and can contain a variety of powersources, including generators powered by I.C. engines, turbine-poweredauxiliary power units or a variety of power units which are commerciallyavailable or in military supply inventories. As shown in FIG. 59B, theseunits need not extend the full depth of the modules they occupy. Thestern section also includes water jet propulsion modules (782) withtrainable water jets (784) on each side to facilitate maneuvering. Anoptional compact nuclear power module (788) can be installed to provideindependence from refueling, and can be located underneath a bridgemodule (776) or at the top of the ship as shown here.

A substantial portion of stern section (763) can be power/propulsion“pod” or module designed for easy removal along connections or borders(808). As shown, such a module comprises electrical power module (786),nuclear reactor module (788), auxiliary power-modules (802),electro-steam generator module (804), water jet propulsion modules (782)and propulsion modules (782) and propulsion modules (759).

FIG. 60 is a side view of one layer (798) of hexagonal boxesinterconnected to form a honeycomb array which can form one deck of aship (800) or other floating structure. Joints (771) indicate where thevertical edges of the hexagonal boxes and half boxes are interconnectedto form a flush side for the vessel (800). Bow thruster propeller (798A)indicates the bow portion of this unit. Internal decks or partitions(797) can be provided within any of the modules using any suitablematerials and methods.

FIGS. 93, 94 and 95 (side and top views, respectively) illustrate theapplication of such a floating platform 798 made up of at least onelayer of hexagonal modules (boundaries 798B indicating theirinterconnections in FIG. 93) as the hull of a houseboat or other vessel821.

Arrangements of rectangular boxes 100 as shown previously in FIGS. 49and 50 can be used to form a superstructure 822A for specific spacesdesigned for living, work or recreation (not shown here). There arevarious ways of arranging the topside space in accordance with thedesires of the owner, using at least one layer or “story” of modules orvertical arrays of suitable length to form the superstructure. Livingand working quarters are built on the decks formed by the hexagonalmodules. As shown in FIG. 94, four rectangular modules 100 areinterconnected to form superstructure 822A, with subdivisions, windowsand doors (not seen here) provided to serve functions includingbedrooms, bathrooms, kitchen and dining areas, recreation and workingareas as needed. A small pilot house 824 is set atop superstructure 822Aand contains various sensors and control means as required. Thesesuperstructure modules could be made of lighter materials, but still ofrectangular or alternatively hexagonal modules 751, as shown in FIG. 95as superstructure 822B. The rectangular and/or hexagonal modules usedcould be of various sizes, but preferably the rectangular boxes 100 areof intermodal sizes and proportions to facilitate transport frommanufacturing plant to assembly site for the houseboat, other vessels orfortress-like bases.

Platform 798 is designed with at least one layer of hexagonal boxes 751which will carry the expected load of the superstructure in a stablemanner without exceeding the draft for the waters where the vessel willbe moored or operated. While a platform with a defined tapered bow 823as shown is desirable for a vessel which will be frequently moved byself-propulsion (e.g., a suitable inboard power plant and at least onepropeller 798A) or towing, a houseboat which is to be permanently mooredor anchored could be substantially rectangular.

Some advocate avoiding building homes on waterfront property which issubject to erosion and interference with the natural forces in the beachenvironment. In lieu of this people could live on floating homes usinghexagonal modules along with half-hexagonal modules and triangularsections made by connecting the two ends of two adjacent sides of ahexagon with a straight line. In this fashion a boat can be made ofmodules having at least three sizes and/or shapes, where each areindependently waterproof. Therefore the vessel would be very unlikely tosink, since many failures of modules would have to occur to allownegative buoyancy. The modules should all be substantially watertight.Most are used for buoyancy, while others can be tanks for fresh water,fuel, or waste as described above for other types of vessels. A fewmodules could be used for storage and machinery. Some on the peripherycould be used for ballast, generating energy from waves, or trimming orstabilizing the vessel, as disclosed elsewhere herein.

Further, in residential or industrial areas subject to shallow flooding,houses or other buildings could utilize a hull containing hexagonaland/or rectangular modules as a waterproof foundation and basement. Inareas prone to deeper flooding, such floatable “houses” could actuallybecome tethered “houseboats” and survive floods relatively intact byrising with the flood waters. Even though a rising tide might not“elevate all boats”, structures mounted upon what are effectivelyfloatable foundations would have vastly improved chances of survivingmost floods. In such configurations, some of the modules used toconstruct the floatable “basement” could have the capabilities to takeon and expel ballast water to prevent undesired floating during a low ormoderate flood.

FIG. 97 provides an example of a watertight basement and foundation 1100which could be installed either in the original construction of a houseor constructed under a house which has been elevated above its originalfoundation. Basement 1100 is constructed of a series of rectangularboxes 100 (preferably of precast concrete) which are fastened securelytogether with suitable mechanical fasteners and/or cement as describedelsewhere herein (not shown here). The sides and ends of boxes 100 thusform both the outer walls of the basement 1100 and partitionssubdividing the space therein. Although not shown extensively here,portions of these inner partitions can be removed or breached to allowpassages such as 1118 between the subdivided spaces, preferably beingfitted with watertight doors 1116 which can be closed in the event offlooding. Conventional doors (not shown) can be used day-to-day, withthe watertight doors kept open and in reserve.

Watertight doors are commonly used in marine construction and arecommercially available, as well as through Navy or maritime salvageyards. They generally include a series of hinges which can be rotated toengage with brackets or “dogs” in the doorway and press the door's metal“knife edge” firmly against a resilient gasket to seal the doorway. Theoptimum form provides a master lever to rotate all these partssimultaneously to provide a convenient means of opening and closing thedoor and sealing the knife edge effectively against the gasket.

At least one garage 1114 is provided within basement 1100, with doorway1112 having twin doors 1110, which may be watertight. In this depiction,the basement 1100 is secured to the surrounding earth using a number ofcables 1104 attached to screw anchors 1102. Windows 1106 can beprovided, with watertight shutters 1108 to be closed when necessary. Asmentioned above, such watertight garages can be provided with pumps,hoses and other suitable equipment as described elsewhere herein toballast, deballast or pump the various spaces dry, depending upon thecircumstances. It may be necessary to provide flexible or detachableutility connections in case floods lift the basement off its footings.

FIG. 61 is a side view of a portion (799) of a vessel (800) or otherfloating structure including four layers or decks of interconnectedhexagonal boxes in honeycomb arrays. As with any multideck ship, theprinciples of naval architecture can be employed to provide fordifferent functions on different decks, ladders, scuttles or otherconnections between decks, watertight integrity, etc. The hexagonal andhalf-hexagonal boxes meet in vertical joints (771). As an alternative tomultiple layers or decks of honeycomb arrays (wherein solid horizontallines indicate the boundaries between layers), the structure can be atleast partially formed of relatively deep hexagonal boxes containingmultiple decks (797) therein. Ladder (806) is exemplary of access meanswhich can be provided within modules or between decks or module layers.Elevators (809) (shown schematically) can also be installed withinmodules. The lower modules or portions thereof can be designated astankage, to improve the stability of individual modules (when afloat) ofthe ship or other floating structure containing such modules.

For the modular vessels described above as well as hexagonal modularfloating platforms for various applications, there may be a need to havea system to raise or lower the ship or platform draft, correct a list ortrim due to loading or battle damage in a static condition. Furthermore,a dynamic system located in the outboard modules to minimize roll orpitching may be desirable for smaller versions of the platforms. Thisallows water to be blown, flooded or pumped to minimize any rolling orpitching of the platform in a seaway or even restricted waters duringstorms.

By having some of the bottom tanks in the outboard modules along thelength of the ship or platform open to the sea, high pressure air fromthe other tanks can be used to blow ballast water out of an open bottomor through an open flood and drain opening. By venting air above theair-water interface, ballast water can be flooded into the tank toincrease the draft and mass of the platform. By flooding or blowingballast out of selected ballast tanks, the trim forward and aft or listport or starboard can be corrected for load imbalance or battle damageflooding.

In a storm, small versions of the hexagonal module platforms may besubject to pitch and roll motions. These dynamic accelerations may bedampened by blowing or flooding tanks and/or pumping liquids from tankto tank, in order to counter such motions. This may be needed only incertain circumstances such as launching or recovering aircraft orsmaller seacraft from a “SEABASE” platform.

FIG. 79 shows a sectional side view of a small platform 1060,representative of various floating platforms and vessels, formed ofhexagonal modules 751 and half-hexagonal modules 753 (not seen in thisview), floating in ocean 954. Modules 751 are shown on each side as opento the sea through their bottom surfaces using at least two one-waycheck valves per module and allowing water flow in or out as shown byarrows 1051. These valves are hinged (at 1061B) to allow them to open asshown when pressure is applied from above, and to swing shut to stopwater flow due to underwater hydrostatic pressure when pressure fromabove is removed. Extended portions 1061A can be provided on theopposite sides of the hinges 1061B from the valves themselves to be usedin combination with electromagnets on the bottom surfaces of thesemodules (not shown), plus suitable switching equipment (not shown), tomaintain the valves in closed position when not ballasting ordeballasting. (Details not shown here.)

This is a schematic representation illustrating that a platform asrepresented by 1060 should have at least one such open module on eachside (e.g., port and starboard) and suitable pumping and control meansto achieve the desired objectives of minimizing roll and/or pitch. At aminimum, such a platform might have only two open modules at opposingcorners (for a substantially rectangular platform), at least one modulein each corner to control roll only, or optionally at least oneadditional open module on the forward and after surfaces or corners tocontrol pitch. Preferably, a plurality of open modules and suitablepumping, valve and control means are provided on each of the side andend surfaces of the platform to effectively control both roll and pitch.

Again as shown in FIG. 79, at least a portion of at least one module 751adjacent the bottom of platform 1060 on each side is open at the bottomto allow ballasting with water. The ballasting volumes or air chamberscan include open portions 1062 of at least one module 751 in a verticalarrangement, as illustrated here. Air and/or water pumping means 1054are provided amidships or another suitable location, connecting topiping 1025 which extends into the air chambers 1062 of modules 751 oneach side. Multiple pumps 1054 can be provided for redundancy andsufficient capacity to service multiple open modules on at least twosides of the platform.

Suitable control means, electric power and signal connections (shownschematically as 1055) connect to pump(s) 1054 to activate pumps asneeded to control ballasting, roll and pitch and other functions asrequired based upon sensors such as inclinometers, angular velocitysensors, accelerometers, gages for external sea pressure and the like(shown schematically as part of control module 1055). Pump(s) 1054connect to suitable valving (not shown here) to pump air into or out ofair chambers 1062 of modules 751, as shown by arrows 1056 and 1058.Pumping air into such chambers will force water in these chambers outinto the sea through check valve(s) 1061, as indicated by arrow 1051,while exhausting air from such chamber(s) will allow water to enter thechamber(s), also through two opposite one-way check valve(s) 1061. Thisis similar to classical systems for blowing and ballasting tanks open tothe sea as used on submarines as well as roll stabilization systems forsurface ships, so suitable control means, valving and the like arereadily available.

Each vertical set of modules is also equipped with piping 1025 extendingfrom the lower portions of air chambers 1062 (to point 1059) to upperportions of the platform for venting and using valves 1044 to openpiping 1025 to high pressure air tanks (not shown here). Water and/orair pumps 1054 can be used to transfer air and/or water depending uponwater level, and thus can be used for wave energy conversion, asdescribed herein with regard to FIG. 80. At higher water levels, watercan be transferred from air chambers 1062 to trim platform 1060 and forstatic and dynamic stabilization. At lower water levels, high pressureair can be used to blow water from chambers on the platform's port orstarboard sides as needed to mitigate roll in high seas.

One feature of massive fixed or floating structures is that the oceanwaves rise and fall relative to the structure without moving itsignificantly. The wave energy can thus be extracted as it compressesand rarefies air above a column of water in a module open to the seabelow. By using one-way check valves, the air on both compression andrarefaction cycles can be sent through an air turbine which can generateelectricity for immediate use or storage in batteries for later use.

As shown in FIG. 80, a representative energy conversion unit 1030 set inwater 902 includes a circular casing 1032 installed within a hexagonalmodule (not shown here) which may be a part of a floating platformcomprising an array of such modules. Water enters intake line 1042 atentrance 1041 and is able to pass into the apparatus via check valve1044, which prevents the water from backing up into intake line 1042once past valve 1044. This water enters high pressure cylinder 1038. Alarge disc-shaped piston 1034 is exposed to the water at the open bottomof the hexagonal module within which casing 1032 is mounted and canslide up or down within casing 1032. Small piston 1043 is mounted atoplarge piston 1034 and fits into small cylinder 1036 so that it can slideup and down with the movements of large piston 1034. Water pressure onthe bottom of large piston 1034 presses water through high pressurecylinder 1038 and through outlet 1039 to a separate pressurized tank ofwater (not shown here). At the same time, air within the space betweensmall cylinder 1036 and casing 1032 is compressed and passes through airturbine generators 1040, which can generate mechanical or electricalpower for direct use and/or charging batteries.

In summary, using a differential area piston with the large area subjectto small variations of water pressure, a greater pressure can begenerated in proportion to the ratio of the large area to the smallerarea of the piston rod acting in a smaller cylinder, where the sameforce acts on a small area. In this manner, using check valves, watercan be pressurized in a volume tank with an air bladder to be used forvarious purposed such as flushing, fire fighting or washing down.

A similar application using high pressure sea water, preferablygenerated by wave energy as discussed above, is to make fresh potablewater (i.e., desalinization) using apparatus comprising at least onesemi-permeable membrane. Such membranes are generally formed ofpolymeric materials, sometimes containing zeolites, and are commerciallyavailable. The fresh water molecules pass through such a membrane byosmosis and the brine left behind can be discharged overboard. In timesof no waves or wind generated swells, a high pressure pump using otherenergy sources such as solar, wind, fuel cells or fossil fuels canprovide the needed pressure for making fresh water. This could be a moreefficient and cost-effective way to obtain the fresh water essential forlengthy operations on station when compared with conventional freshwater evaporative stills, especially when operating in tropical waters.

In the floating platforms and vessels disclosed herein, various spaceswithin the modules will be occupied with fuel, weapons, supplies ofvarious kinds and spaces for crew messing, berthing and recreation. Suchfeatures are disclosed in connection with the vessels of FIGS. 57 and58, and will not be shown for each platform or vessel disclosed hereinfor particular purposes. A representative example is shown in FIG. 120,a hexagonal array or column 801 of hexagonal modules 751 which forms aportion of a grand horizontal array. Horizontal separation lines 751Abetween separate modules can be seen, and the vertical module wallintersections 751C are also visible. Here, the upper module is devotedto hangar space 834 for helicopters or other aircraft, the middle moduleis utilized for machine shops 836 or the like and the lower module isused as a fuel tank 809. Similar or different allocations of verticaland horizontal spaces within a large floating platform will be madeaccording to the size, mission and manning of the platform. Similarly,the roll stabilization and wave energy conversion systems disclosedabove can be used with many of the useful platforms and vesselscomprising the hexagonal, half-hexagonal and rectangular modulesdisclosed herein.

In addition to the detachable bow and stern sections disclosed inconnection with FIGS. 57 and 58 and the joining of arrays of hexagonalmodules into larger arrays or platforms (much like making up a log boom)depicted in FIG. 98, large hexagonal modules or arrays comprisingpluralities thereof can be included in such platforms as removablyattachable components thereof. Such detachable floating modules orarrays can be used for a variety of purposes, but an important exampleis the floating lifeboat or escape module 1068 shown in FIG. 96.

This detachable “vessel” comprises at least one hexagonal module 751 andoptional half-hexagonal modules 753 as may be required to provide ashape which is easily detached from the min platform along lines ofseparation and can be navigated in open waters. At least one hatch 1069is provided in upper surface or deck 751A of the vessel, and an elevatedportion 1071 (comprising smaller hexagonal or rectangular modules or anysuitable superstructure materials) contains space 1072 for command,control and communications, using at least one antenna 1073. An upperlevel such as 1070 can contain cooking, dining and recreation areas,while levels just below can contain berthing and medical care areas.Tanks 809 for fuel and water are provided at the lowest levels, wherethe weight of liquids will serve to ballast the vessel and stabilize it.Levels above these tanks can be devoted to storage (805B), power andauxiliary areas. Such vessels can be anchored or mobile, and severalcould be deployed in an operational area as weather stations, earlywarning sensor platforms, communications links and the like. Smallerversions such as a single floating, vertically oriented hexagonal modulecould be used as an anchored ocean sensing buoy. Such hexagonal buoyscould be transported to their ocean locations as part of an array ofsimilar hexagonal modules incorporated as the midship section of amodular vessel and dropped off one at a time.

FIG. 62 is a top view and a FIG. 63 a side view of a hexagonal precastconcrete box (751) as discussed for use above. Internal reinforcingmaterials are cast within the concrete to enhance strength. A pluralityof reinforcements (780) and (781) are connected between the corners ofthe box, cast within the bottom, top and sides of the box. Thesereinforcements can be nonmetallic rods, mesh, tensioning cables, rebar,metal beams of various cross sections, or other suitable materials.Supports (765) are provided along at least a portion of the horizontaland vertical edges (751A and 751B) of the boxes. These can be round orpolygonal cylinders, or standard angle iron formed of metals or othersuitable materials such as polymer composites, inserted in the molds sothat they are cast into the concrete during fabrication. An “angle iron”signifies an elongated sheet of metal (or other suitable material) bentto include an angle of about 90 degrees. For these hexagonal boxes, theangle can be about 120 degrees (to fit the box edges), but commerciallyavailable angle iron stock can be readily used, as the majority of thesupport will be cast into the concrete, leaving the edge exposed toprotect the box edges from damage. Optionally, angle irons comprisingferrous metals can be galvanized or otherwise treated to resistcorrosion. The supports and other reinforcing materials can beinterconnected by suitable mechanical fasteners to form a frameworkresembling a cage which will retain its shape during casting and provideresistance to damage when the concrete boxes are cured and put into use.Suitable mechanical connecting means (774), as disclosed above and inthe drawings as connectors (150), are provided at the corners asrequired to interconnect the boxes to form a honeycomb array.

The hexagonal and half-hexagonal boxes can be cast using typical molds,with provisions for the inclusion of reinforcing rods (rebar),tensioning cables and supports for the edges thereof, using methodssimilar to those used for the rectangular boxes disclosed herein and inthe previous U.S. Pat. Nos. 5,697,736 and 5,697,052.

FIGS. 81 and 81A show top and side sectional views, respectively, ofhexagonal concrete modules 751 presently cast for employment byApplicant's companies and licensees to use in shoreline installations.Module 751 has a flat bottom 751A of uniform thickness and six verticaloutside walls 751B, with the thickness of these walls increasing fromtop to bottom. This is to provide sufficient clearance or “draft” forthe casting to be easily removed from the mold. Normally sufficientclearance will be provided by allowing about two inches difference inthe wall thickness for a six foot tall module, or equivalent proportionsfor other sized modules. However, when individual cast modules are to bestacked together to form integrated columns, stacks or “caisson” units,walls of uniform thickness may be preferable. Forms to accommodatecastings without draft would be employed in such cases.

Similar casting techniques can be used for casting modules with othercross sections, such as triangular, half-hexagonal, pentagonal oroctagonal if required; the hexagonal and half-hexagonal versions arepresently preferred due to their ability to produce structures havinghigh strength-to-weight ratios when joined in arrays. Reinforcingmaterials of metal or other suitable materials can be included in theside walls and/or bottom as discussed above with regard to FIGS. 62 and63. Optionally, a plurality of holes 767 as shown can be cast into thewalls by plugs in the mold, for the purpose of filling and draining themodules and/or connecting adjacent boxes together side-to-side to formlinear arrays. Temporary plugs can be installed in these holes whilefloating the modules to designated locations.

The hexagonal modules 751 can have an inner cross section that can behexagonal or circular. While the hexagonal shape inside and out providesuniform wall thickness as shown in FIG. 82, in some cases one might wantgreater strength at the intersections of the outer hexagonal sides. Thecircular inside cross section shown in FIG. 83 provides this, which alsomay be more desirable for any number of module uses to constructfloating base platforms, such as a missile silo or an enclosure for alarge sensor, weapon or mechanical device that must rotate through 360degrees.

The hexagonal modules 751 and vertical arrays thereof can have a numberof decks and compartments installed. As such, since each module isindependently waterproof, and normally there is no access providedhorizontally between adjacent modules, a central ladder or elevator isuseful for vertical access. Should horizontal access between modules bedesired, a deck level could be chosen at approximately mid height forthe installation of watertight submarine doors. As shown in FIGS. 84 and85, a column or vertical array 801 of several modules 751 can besubdivided by the integral module bottoms 751A and/or additional decks797 to provide spaces for purposes comprising berthing areas 803,storage levels large and small (805A and 805B, respectively) and tankspaces 809, normally at lower levels to facilitate ballasting and reducethe center of gravity of column 801 and the metacentric height of theoverall floating structure containing such columns. As shown in FIG. 85,each deck level can be subdivided vertically by bulkheads or partitions815 into a number of segments, up to about six (depending upon the sizeof the module) for various uses such as berthing, offices, or storage toprovide more privacy and bulkhead space as needed.

There will be a need for pipes, power cables, communication lines,ventilation and similar communications passing through and between themodules as well. These lines can pass through passages 811 inside thehexagonal module at the wall intersections 751C as in FIG. 82, or inconduits cast into the thickened intersection 751C of FIG. 86. Secondly,vertical access for cables, wires, pipes and ventilation can beinstalled in a central core 813 installed in a module 751 as in FIGS.85, 86 and 87. Such vertical shaft surfaces (inside and outside) can betwo concentric circles, two hexagons, or combinations as desired. Thesecores can be of any suitable cross section, such as hexagonal (FIGS. 87,85) or circular (FIG. 86). Such central cores will also strengthen thedecks by reducing the unsupported span of the deck levels.

As shown in FIG. 88, hexagonal modules 751 can be cast with notches 751Daround their bases or bottoms 751A which provide a small hexagonalprojection which will fit snugly in tongue and groove fashion into theopen top 751E of an adjacent module in a vertical array or column. Thispermits a number of such modules to be joined top-to-bottom to form amore securely joined “stack” or column 801, as shown in FIG. 89 and inthe top view of FIG. 90. Any of the hexagonal and other types of modulesdisclosed herein can be cast with open bottoms 751A and tops 751E, asshown for module A in FIGS. 88 and 89. This permits individual modulesto be assembled into columns 801 having a larger proportion of theirlongitudinal space open inside, depending upon the requirements of anindividual assembly or structure.

FIGS. 91 and 92 illustrate the use of a floating drydock as a mobileplatform to set up a precast concrete assembly plant for the productionof precast rectangular, hexagonal or other concrete modules. In order toefficiently produce concrete products primarily for shipping by water,the plant's output should be on the water. Because much of the cementand sand are cost-effectively also shipped by water, the plan depictedin the drawings is offered as perhaps the most efficient way to designsuch a plant.

The main concrete plant could be built on a pier or a floating drydockmoored with the aft end fast to the land or wharf facility in thefashion known as a “Mediterranean moor”. Then barges or smaller coastalships can come alongside the drydock or pier to unload cement and sandfrom the barges directly into the plant as necessary. Crushed stone,aggregate, steel, carbon or other reinforcing fiber, personnel, etc.could come by land or also by barge alongside. The finished productcould be loaded on a barge or ship from the seaward end of the plantwhere the water is deeper.

Floating drydocks generally have overhead cranes which would be usefulfor the concrete casting operation and may be available surplus, as ournational shipbuilding and repair business has declined. Also, some ofthe products may be compatible with using a tug, integrated tug-barge(ITB) or specialized ship to transport the modules as a floatingassembly directly to the desired location for use.

Time-motion studies should prove the efficacy of a system where bulkmaterials can flow into the port and starboard sides of a precastconcrete plant established on a floating drydock; personnel, smallercomponents and services are brought in from the landward end; andproducts are offloaded to transport vessels on the water on the seawardend of the plant. Furthermore, such a plant can be relocated closer tothe next job site after the current work is finished for efficiency.

FIG. 91 shows an end view of an open-ended floating drydock 820 withcharacteristic pontoon hull 826 and side walls 822 afloat. As seen inFIG. 92, it is moored astern to a pier 934 (mooring lines omitted forclarity). Barges 930 and 931 are moored alongside drydock 820 to portand starboard, respectively, loaded with cement 932 and sand 933. Crane830 can be moved along side walls 822 of drydock 820 to pick up formsand finished rectangular and hexagonal modules (100 and 751,respectively) via crane hoists 831. Forms for both hexagonal andrectangular modules are shown in this example. Concrete can be mixed ina large facility ashore or on pier 934, or reinforcing steel 936 andaggregate 938 can be transferred to drydock deck 829 from pier 934 andcombined with the cement and sand to produce concrete aboard in a mixer(not shown here) so that it can be conveniently poured into molds. Withsufficient space, this can be run as a sort of assembly line, withconcrete poured into a series of prepared molds, the molded modulesallowed to cure for a minimum period of time and then picked by crane830 to be moved toward the drydock bow 837 where forms and moldedproducts are separated. The forms are then returned to the molding areato be prepared for further molding operations.

While the hexagonal and half-hexagonal boxes of the invention have beendescribed for use in fabricating modular ships or other floatingstructures, they can be used as well in constructing shorelinestructures as disclosed above and in previous U.S. Pat. Nos. 6,491,473and 5,697,052, which can be attached to the shore above high tidelevels, on the bottom or in floating structures attached to theshoreline or sunken structures, all in honeycomb arrays to takeadvantage of the high strength-to-weight ratios. Floating structuresincorporating honeycomb arrays of these hexagonal modules can betransported by the vessels disclosed herein and assembled in remotelocations to form complex floating structures which can serve asfloating bases for a variety of aircraft, small craft and ships forvarious civil and military purposes. For example, such floatingplatforms, which can include self-propulsion and defense means, could beused to support combat or patrol operations, rescue efforts for nationaldisasters such as Hurricane Katrina of 2005, exploration and productionof minerals or oil, maritime construction projects, floating “SEAHOUSE”communities and the like.

Hexagonal modules of the invention can be used to great advantage,either combined together into various types of arrays or in combinationwith the rectangular modules and other structural components discussedabove for constructing shoreline structures such as seawalls, bulkheads,jetties, groins, piers and breakwaters, the latter of which may be atleast semi-submerged depending upon tidal state. For example, FIG. 102illustrates a linear array of hexagonal modules 751 implanted in thebeach 1125 (using techniques discussed in detail above) along ashoreline or bank 402 to form a seawall or bulkhead 1122. The lineararray forming most of the structure can be a single linear array withthe angular indentations where the modules meet left exposed to exertbeneficial effects upon the effects of water upon the beach andaccretion of sand and gravel. Alternatively, half-hexagonal modules 753could be used (as described above) to create a flush surface facing thewater or elsewhere as desired.

This figure illustrates how hexagonal and (optionally) half-hexagonalmodules can be assembled to create branches extending at angles ofapproximately 60 or 90 degrees to the basic linear array to follow acurving shoreline contour or form the beginnings of a groin or pier.Here, two modules 751 are used to create branch 1123 forming a 60 degreeangle to seawall 1122 and following the contour of shoreline 402. Suchadjustments may be necessary to follow a curved natural bank or match upwith a structure on adjacent properties, or can be used to provide anangled seawall to influence the flow of water and the deposition of sandand gravel. Three modules 751 are used here to form a roughly triangularsection 1124 approximately perpendicular to the seawall. Such aprojection could be used for space for a patio, gazebo or otherrecreational use, or with the use of half-hexagonal modules (not shownhere) could be the base for building a groin or pier some distance outtoward the waterline 1126.

In addition to their usefulness in constructing shoreline structures,arrays comprising hexagonal, half-hexagonal and optionally rectangularmodules can be used in various configurations as breakwaters, whichwould be installed offshore from the beach and roughly paralleling it(dependent upon the direction of prevailing or seasonal winds andwaves). Modifications to straight linear arrays, extending eitherlandward or seaward, such as branch 1123 and triangular projection 1124on array 1122 can be designed to deflect waves and/or winds when suchbreakwaters are installed at least partially submerged in the water 952.

FIGS. 103 through 106 illustrate forms of assembling the hexagonalmodules 751 which can be useful in various structures, whetherterrestrial, shoreline, floating or submerged. FIG. 103 illustrates adouble linear array or wall of modules 1130 with the intersections ofmodules left open to form a “sawtooth” edge or surface on both sides.FIG. 104 shows a combination of hexagonal and half-hexagonal (753)modules used to form a linear array 1132 the width of one module andhaving a flush surface on both sides. FIG. 105 shows the use ofhexagonal and half-hexagonal modules to form a portion of a linear array1134, having the width of two modules and having flush surfaces on bothsides.

FIG. 106 shows the use of hexagonal modules 751 (and optionally,half-hexagonal modules to form a flush riverside surface) to form adurable levee or harbor wharf 1136 approximately two modules deep (ormore, as needed) set into the river (or harbor) bottom 903 and riverbank (or harbor surface) 905. Such a structure can be structured as awharf for ships 1135 of various sizes (depending upon available spacefor length, local draft and other conditions).

A larger version of such construction can be seen in FIG. 107, providinga sheltered harbor or offshore “SEACASTLE” port facility for a varietyof ships and smaller craft, as described below.

The same large size hexagonal modules which could be used for mobile“SEABASE” platforms could also be used for a floating or bottomedmodular port facility. Such a facility could accommodate large deepdraft ships, which could not enter shallow ports, much like oil pumpingplatforms are used to load modern supertankers. Also for securityreasons, the use of such port facilities could enable cargo to beinspected some distance from existing port facilities located nearpopulation centers.

If floating, these massive ports would be secured to the bottom withlarge anchors. Screw anchors and multi-point mooring systems similar tothose used for large floating oil drilling rigs could be used.

If bottomed, the modules could be flooded to gain mass and weight toassist in jetting them into the bottom. Selected corner modules could betaller ones, which could be jetted deeper into the bottom. Their bottomsections could be filled solid with concrete for greater strength at thecorners. Like the towers at the corners of castles and fortresses, thesetaller modules would have a good view of two sides of the port as wellas an elevated view of the activity on the port's surface.

The inboard side of the fortress-like “SEACASTLE” port would beprotected from wind and large waves. There, pilot boats, smaller coastalships, barges, tankers, hovercraft and smaller ferry and personnel boatscould moor. Large container, freight, bulk and tanker ships couldtransfer their cargo directly across the narrow sides of the facility toinboard ships without temporarily storing the material at the port.Further, trains and trucks could access a nearby shore port viaconnecting means such as causeways or tunnels. Similarly, pipelinescould pump liquids ashore for storage and further distribution to trucksand tanker rail cars. A large tube with massive mechanisms similar to agondola ski lift could transport containers on rollers, rails or thelike to a land based facility for further shifting to trucks, trains,barges or storage.

The hexagonal modules in relatively larger sizes (e.g., from about 24 to160 feet high and about eight to sixty feet wide between flat sides) areideal to use alone or as components of floating or fixed port facilitiesinshore or in offshore waters. If they are to be fixed to the bottom,they could also be jetted down into the sand or mud bottom and thenballast water pumped out to “tune” the units to a neutral buoyancy toprevent further subsidence. If the bottom is hard, then the ballastcould be maximized to achieve the greatest mass to resist storm wavesand currents.

FIG. 107 illustrates a representative use of linear and vertical arraysof hexagonal and half-hexagonal modules (751 and 753) to form a roughlyrectangular port facility 1200 with exterior wharfage for large shipsand interior wharfage for smaller vessels. Such facilities can be laidout in any suitable shape, employing the angular combinations possiblewith hexagonal modules. As illustrated in FIGS. 102-106, such modulescan be assembled to form walls of single or double thickness, with flushor sawtooth surfaces. At the top of FIG. 107, a large freighter 1202(with a shipping container 100 on deck) is shown moored (mooring linesomitted for clarity) to a wharf formed by the uppermost wall of theport, representing the seaward or most exposed side of the port. Atleast one rail line 1204 and associated crane 1206 can be provided forfueling and/or loading or offloading containers or other freight fromsuch ships. A series of offloaded containers is shown at left enteringtunnel 1212 and proceeding through the tunnel to a destination. A numberof smaller vessels 1208 are shown moored to wharves formed by the innersurfaces of the port's walls, which can have either flush surfaces (theuppermost surface) or sawtooth (those at left and right). They are ableto enter the port 1200 via an inshore entrance 1203. A bridge, causewayor tunnel 1210 joins the port at the lower left to provide access toland or another platform. At least one tube or pipeline 1212 can providefuel or cargo from outside the port and/or transport liquids such aspetroleum products which have been offloaded by ships such as 1202. Suchtubes can be used to move containers to shore via conveyor belts orrollers, as discussed for the tunnel 1212 at left. A medium-size vessel1214 is shown moored to the wharf formed by the lower (inshore) outersurface of the port.

For Homeland Security, a permanent facility at the entrance or slightlyoffshore of some existing port entrances would be desirable. Such afacility could be either floating or fixed to the bottom. Location wouldbe based on site conditions such as currents, tides, prevailing windsand waves, geographic protection, bottom material, etc. At least onemodule would be taller than the rest to provide a central control andobservation location.

Besides providing radar, lasers, visual observation, communications andother electromagnetic signatures and coding such as IFF etc., the “SeaSentinel” Base could be a check-in location, inspection station, andtraffic control tower for a busy port. Coast Guard helicopters andpatrol craft as well as immigration, agricultural and Homeland Defensepersonnel could serve as the initial filter for the port at somedistance from the main facilities and population centers.

In most cases an entrance on the leeward side protected from waves bynatural geological features could protect the facility. A breakwatercould provide protection if no natural features exist. In locationswhere rough water may be commonplace, an area of calm water could beformed by a modular breakwater comprising hexagonal and/or rectangularmodules.

A movable entrance to the base can be designed to open or close asneeded. One way is to have one of the hexagonal (or rectangular) modulessplit horizontally. The top half would be capable of being madeneutrally buoyant and hinged so that it could be swung open and closedlike a gate or door, using suitable mechanical means such as cables on awinch.

A second method would be to have one or more modules which could beshorter in length be connected by rails to their fixed neighbor modules.These modules could be moved up or down by blowing water ballast out toraise and close or flooding ballast to sink the “gate” to allow surfacetraffic in or out, as described above for a water gate system.

FIG. 108 shows such a platform 1140 comprising an array of hexagonal andhalf-hexagonal modules (751 and 753), with a control and observationtower 1142 on one corner which has an elevated portion 1144, alsohexagonal in form. The sides of the platform are left in a sawtoothconfiguration, except for the lower edge 1146 which provides mooringspace for a vessel 1148 such as a small Coast Guard cutter and/or smallcraft.

FIG. 109 shows a larger platform 1150, also formed of hexagonal modules751 and providing interior space 1152 which is made accessible toshelter small craft. An observation and control tower 1142 with elevatedportion 1144 similar to that of FIG. 107 is provided. As outlined above,at least one module 1154 can be displaced to provide an entrance 1158which will allow access to interior basin 1152 and can then be closed.For example, winches 1157 and cables 1159 attached to module 1154 can beused to move module 1154 one way or the other to open or close entrance1158. Flush surfaces for mooring can be provided by use ofhalf-hexagonal modules. In this case, module 1154 can be moved on hinges1156 by any suitable means. Alternatively, at least one module or alinear array thereof can be provided with ballasting equipment so thatit can be ballasted and sunk, sliding along tracks or grooves, to openthe gate and then deballasted to raise the module and close the gate.Details of such apparatus are illustrated and described above inconnection with FIGS. 75-78.

Some applications of precast concrete boxes of the invention forshellfish habitat are illustrated in FIG. 51. In many areas, thecultivation of shellfish such as oysters and mussels has been adverselyaffected by pollution and silting of bottoms of bays and other bodies ofwater, which may be exacerbated by harvesting techniques which disturbbottom sediments. To permit the cultivation of shellfish above thebottom in such areas and facilitate harvesting without aggravating suchproblems, FIG. 51 provides a precast concrete box (700) with enclosedsides containing holes (702) and/or slots (704). As illustrated in FIG.4 above, these openings can be at least partially filled with breakable,thin concrete sections to provide knockout areas to facilitate thesinking of the boxes. The openings in the box permit its use as shelterby small fish, crabs, crustaceans and shellfish. Although the box couldbe raised by filling it with ping-pong balls, styrofoam particles,inflatable balloons or the like, because of its weight this embodimentis more suitable for use as a permanent seed bed to remain on thebottom.

The boxes are provided with removable concrete tops (710) which can beheld in place with pins (708) passing through holes (706) in both coversand the corners of the boxes. Shellfish are to be cultivated on thecovers of the boxes when sunk into place, thus elevating the shellfishat least the height of the box (perhaps 4 to 8 feet) above the bottomwhere they are removed from silt and pollutants and exposed to currentscarrying more nutrients and oxygen. The boxes preferably have dimensionsand proportions which permit intermodal transport and the covers areprovided with various types of projections or roughened surfaces topromote adhesion by shellfish spat. This working surface of the coversis turned inward for convenience in transport, then is reversed andsecured in place before sinking and installation of the boxes. In FIG.51, cover (710) is covered with at least one layer of projections (712)(here, three layers) having the form of rectangular parallepipeds, whichcan be laid down horizontally in criss-cross patterns as shown. Inaddition to producing boxes and covers of concrete comprising crushedbivalve shells, preferably oyster shells, the projections (712) can becast or otherwise produced of similar materials. The objective is toprovide rough, porous surfaces which are hospitable to shellfish spat,with projections which are spaced appropriately to foster rapid andproductive growth of the shellfish to harvestable size. As analternative or addition to such projections, the covers can be cast tocontain large fragments of broken bivalve shells, as shown in FIG. 52 as(717) on concrete cover (710). This in itself could provide an idealoyster bed, but oyster shells and comparable materials are in shortsupply and must be conserved. Also shown in FIG. 52 are rectangularprojections (714) which are cast or attached perpendicular to cover(710).

FIGS. 53 and 53A illustrate another type of shellfish habitat, with FIG.53 schematically illustrating a meshwork container (701) with attachmentpoints (726) at the upper corners for attaching bridle cables (728) andhoisting cable (730). Pins (722) are fitted to the lower corners so thatthe container can be mounted atop a precast concrete box such as box(700) of FIG. 51, or any suitable container or platform which willelevate the habitat to the proper level above the bottom. Any suitablemesh or openwork material (733) can be used to construct containers(701) about a suitable framework including rigid components (732),including expanded metal, heavy wire mesh and the like. The verticalsides of the container should be mesh as shown, but the bottom can besolid (725) and/or mesh (723). For durability, meshwork of stainlesssteel or synthetic polymeric materials may be preferred. Container (701)is to be filled with suitable objects for the adherence of shellfishspat, such as used tires (724), optionally filled with broken shells,stainless steel wire mesh structures, plastic pipe reinforced withsteel, fragments of k concrete, and the like, any of which can containbivalve shells or mature oysters.

Two ways of providing inner mesh structures are to install verticalsections of mesh (736) extending from a narrow end of the container(where they attach to frames (732) and/or side mesh (733) to at leastthe center, where they can be attached to wire or rod supports (727).Such vertical mesh sections could extend from one end of the containerto the other. In addition, or alternatively, horizontal layers of mesh(734) can be attached to a narrow end of the container, extendingparallel to the bottom at least to the center of the container, wherethey can be attached to wire or rod supports (729). Such horizontallayers of mesh can also extend the entire length of the container.

A precast concrete top (710), much like that shown in FIG. 52, isprovided. Various types of projections, including those shown in FIGS.51 and 52, can be used. FIG. 53A illustrates projections (716) and(718), which are cylindrical and conical, respectively. Conicalprojections are preferred, as they are easier to remove from the moldsused to cast the assembly. Additional components can be mounted on theseprojections, such as used tires (720), optionally filled with bivalveshells, stainless steel wire mesh structures, etc.

Since container (701) is much lighter than a concrete box, even whenfilled with structures for shellfish culture, hoisting and bridle cables(730) and (728) can be used to lift the entire container, cover and all,or alternatively, similar cables can be connected to lift cover (710)independently. Also, if the container (701) is mounted upon a solidconcrete box such as illustrated in FIG. 15 having apparatus forintroducing air to expel the water, the box itself can be blown andraised to the surface, carrying the container on top. Once eithercomponent (the container or cover) is hoisted clear of the water, thecontents can be hosed off to remove any silt or sand and the assemblyshaken or vibrated over a vessel's deck or hold to dislodge oysters orother shellfish (e.g., mussels) for harvest.

Various changes and modifications to the presently preferred embodimentswill be apparent to those skilled in the art. Such changes andmodifications may be made without departing from the spirit and scope ofthe present invention and without diminishing its attendant advantages.Therefore, the appended claims are intended to cover such changes andmodifications, and are the sole limits on the scope of the invention.

1. A self-propelled vessel for transporting floating objects, comprisingseparate bow and stern sections adapted to be removably fastenedtogether using mechanical means to form the vessel alone and also to beseparated and fastened mechanically to a floating object to form avessel incorporating said floating object as a midship section totransport same, with said bow section comprising at least one anchor,propulsion means, at least one power supply and control means to operatesame and a crane unit, and said stern section comprising a propulsionsystem, at least one anchor, a pilot house and controls for said vessel,said vessel incorporating at least a portion of a floating drydock assaid midship section.
 2. The vessel of claim 1 wherein a substantiallycomplete floating drydock comprising bottom and side hull sections isincorporated as said midship section.
 3. The vessel of claim 1 whereinsaid mechanical means comprise connectors to interconnect said bow andstern sections to each other and said floating drydock and tensioningcables to maintain the position of said midship section.
 4. The vesselof claim 1 wherein at least a portion of said bow section and said sternsection comprise pluralities of precast concrete boxes having ahexagonal or half-hexagonal cross section which are assembled in avertical orientation and interconnected in honeycomb arrays to form thestructure of said bow and stern sections.
 5. The vessel of claim 4wherein at least one of said bow and stern sections further comprisesprecast concrete boxes having half hexagonal cross sections which areinterconnected to the outer portions of said bow or stern section toform flush surfaces for said section.
 6. A self-propelled vesselcomprising separable bow, stern and midship sections, said bow and sternsections being removably attached to said midship section along lines ofseparation by suitable mechanical fasteners, each of said sections beingconstructed primarily of a plurality of precast concrete boxes havinghexagonal or half-hexagonal cross-sections, the majority of saidhexagonal boxes having substantially open and unobstructed inner crosssections, said boxes being oriented vertically and interconnected bymechanical means to form said bow, stern and midship sections into anintegrated hull structure of said vessel, with said bow section havingat least one anchor, propulsion means, at least one power supply andcontrol means to handle same and at least one crane unit for handlingcargo, and said stern section comprising a pilot house, at least oneanchor, at least one propulsion unit and control means for said vessel.7. The vessel of claim 6 wherein a portion of said boxes forming saidmidship section are adapted to serve as tanks for fuel, water andballast.
 8. The vessel of claim 6 wherein said midship section comprisescargo-carrying sections and at least one crane to handle said cargo. 9.The vessel of claim 6 wherein a plurality of said boxes in said bow,midship and stern sections are adapted for special purposes comprisingoperations, engineering, storage, habitability and weapons.
 10. Thevessel of claim 9 wherein at least one of said boxes adapted for specialpurposes is removably attached to an outer surface of at least one ofsaid sections along a defined line of separation.
 11. The vessel ofclaim 6 which comprises at least one hexagonal box or vertical array ofsaid boxes which contains at least one of a vertical ladder or elevator.12. The vessel of claim 6 wherein at least said midship section is largeenough and is adapted to serve as a mobile base for at least one type ofvehicle selected from the group consisting of large ships, smallervessels, small craft, submarines, submersibles, hovercraft, amphibiousvehicles and aircraft.